8 files changed, 1488 insertions, 0 deletions
diff --git a/src/js/contentscripts/clobbercookie.js b/src/js/contentscripts/clobbercookie.js
new file mode 100644
index 0000000..402d00e
--- /dev/null
+++ b/src/js/contentscripts/clobbercookie.js
@@ -0,0 +1,60 @@
+/*
+ * This file is part of Privacy Badger <https://www.eff.org/privacybadger>
+ * Copyright (C) 2014 Electronic Frontier Foundation
+ *
+ * Privacy Badger is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Privacy Badger is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Privacy Badger.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+(function () {
+
+// don't inject into non-HTML documents (such as XML documents)
+// but do inject into XHTML documents
+if (document instanceof HTMLDocument === false && (
+  document instanceof XMLDocument === false ||
+  document.createElement('div') instanceof HTMLDivElement === false
+)) {
+  return;
+}
+
+// don't bother asking to run when trivially in first-party context
+if (window.top == window) {
+  return;
+}
+
+// TODO race condition; fix waiting on https://crbug.com/478183
+chrome.runtime.sendMessage({
+  type: "checkLocation",
+  frameUrl: window.FRAME_URL
+}, function (blocked) {
+  if (blocked) {
+    var code = '('+ function() {
+      document.__defineSetter__("cookie", function(/*value*/) { });
+      document.__defineGetter__("cookie", function() { return ""; });
+
+      // trim referrer down to origin
+      let referrer = document.referrer;
+      if (referrer) {
+        referrer = referrer.slice(
+          0,
+          referrer.indexOf('/', referrer.indexOf('://') + 3)
+        ) + '/';
+      }
+      document.__defineGetter__("referrer", function () { return referrer; });
+    } +')();';
+
+    window.injectScript(code);
+  }
+  return true;
+});
+
+}());
diff --git a/src/js/contentscripts/clobberlocalstorage.js b/src/js/contentscripts/clobberlocalstorage.js
new file mode 100644
index 0000000..7ff3528
--- /dev/null
+++ b/src/js/contentscripts/clobberlocalstorage.js
@@ -0,0 +1,94 @@
+/*
+ * This file is part of Privacy Badger <https://www.eff.org/privacybadger>
+ * Copyright (C) 2014 Electronic Frontier Foundation
+ *
+ * Privacy Badger is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Privacy Badger is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Privacy Badger.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+(function () {
+
+// don't inject into non-HTML documents (such as XML documents)
+// but do inject into XHTML documents
+if (document instanceof HTMLDocument === false && (
+  document instanceof XMLDocument === false ||
+  document.createElement('div') instanceof HTMLDivElement === false
+)) {
+  return;
+}
+
+// don't bother asking to run when trivially in first-party context
+if (window.top == window) {
+  return;
+}
+
+// TODO race condition; fix waiting on https://crbug.com/478183
+chrome.runtime.sendMessage({
+  type: "checkLocation",
+  frameUrl: window.FRAME_URL
+}, function (blocked) {
+  if (blocked) {
+    // https://stackoverflow.com/questions/49092423/how-to-break-on-localstorage-changes
+    var code =
+      '('+ function() {
+
+        /*
+         * If localStorage is inaccessible, such as when "Block third-party cookies"
+         * in enabled in Chrome or when `dom.storage.enabled` is set to `false` in
+         * Firefox, do not go any further.
+         */
+        try {
+          // No localStorage raises an Exception in Chromium-based browsers, while
+          // it's equal to `null` in Firefox.
+          if (null === localStorage) {
+            throw false;
+          }
+        } catch (ex) {
+          return;
+        }
+
+        let lsProxy = new Proxy(localStorage, {
+          set: function (/*ls, prop, value*/) {
+            return true;
+          },
+          get: function (ls, prop) {
+            if (typeof ls[prop] == 'function') {
+              let fn = function () {};
+              if (prop == 'getItem' || prop == 'key') {
+                fn = function () { return null; };
+              }
+              return fn.bind(ls);
+            } else {
+              if (prop == 'length') {
+                return 0;
+              } else if (prop == '__proto__') {
+                return lsProxy;
+              }
+              return;
+            }
+          }
+        });
+
+        Object.defineProperty(window, 'localStorage', {
+          configurable: true,
+          enumerable: true,
+          value: lsProxy
+        });
+
+      } +')()';
+
+    window.injectScript(code);
+  }
+  return true;
+});
+
+}());
diff --git a/src/js/contentscripts/collapser.js b/src/js/contentscripts/collapser.js
new file mode 100644
index 0000000..968905c
--- /dev/null
+++ b/src/js/contentscripts/collapser.js
@@ -0,0 +1,56 @@
+/*
+ * This file is part of Privacy Badger <https://www.eff.org/privacybadger>
+ * Copyright (C) 2020 Electronic Frontier Foundation
+ *
+ * Privacy Badger is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Privacy Badger is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Privacy Badger.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+(function () {
+
+// don't inject into non-HTML documents (such as XML documents)
+// but do inject into XHTML documents
+if (document instanceof HTMLDocument === false && (
+  document instanceof XMLDocument === false ||
+  document.createElement('div') instanceof HTMLDivElement === false
+)) {
+  return;
+}
+
+function hideFrame(url) {
+  let sel = "iframe[src='" + CSS.escape(url) + "']";
+  let el = document.querySelector(sel);
+  if (el) { // el could have gotten replaced since the lookup
+    el.style.setProperty("display", "none", "important");
+  }
+}
+
+chrome.runtime.onMessage.addListener(function (request, sender, sendResponse) {
+  if (request.hideFrame) {
+    hideFrame(request.url);
+    sendResponse(true);
+  }
+});
+
+// check the page for any frames that were blocked before we got here
+chrome.runtime.sendMessage({
+  type: "getBlockedFrameUrls"
+}, function (frameUrls) {
+  if (!frameUrls) {
+    return;
+  }
+  for (let url of frameUrls) {
+    hideFrame(url);
+  }
+});
+
+}());
diff --git a/src/js/contentscripts/dnt.js b/src/js/contentscripts/dnt.js
new file mode 100644
index 0000000..0584748
--- /dev/null
+++ b/src/js/contentscripts/dnt.js
@@ -0,0 +1,66 @@
+/*
+ * This file is part of Privacy Badger <https://www.eff.org/privacybadger>
+ * Copyright (C) 2018 Electronic Frontier Foundation
+ *
+ * Privacy Badger is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Privacy Badger is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Privacy Badger.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+function getPageScript() {
+
+  // code below is not a content script: no chrome.* APIs /////////////////////
+
+  // return a string
+  return "(" + function (NAVIGATOR, OBJECT) {
+
+    OBJECT.defineProperty(OBJECT.getPrototypeOf(NAVIGATOR), "doNotTrack", {
+      get: function doNotTrack() {
+        return "1";
+      }
+    });
+
+    OBJECT.defineProperty(OBJECT.getPrototypeOf(NAVIGATOR), "globalPrivacyControl", {
+      get: function globalPrivacyControl() {
+        return "1";
+      }
+    });
+
+  // save locally to keep from getting overwritten by site code
+  } + "(window.navigator, Object));";
+
+  // code above is not a content script: no chrome.* APIs /////////////////////
+
+}
+
+// END FUNCTION DEFINITIONS ///////////////////////////////////////////////////
+
+(function () {
+
+// don't inject into non-HTML documents (such as XML documents)
+// but do inject into XHTML documents
+if (document instanceof HTMLDocument === false && (
+  document instanceof XMLDocument === false ||
+  document.createElement('div') instanceof HTMLDivElement === false
+)) {
+  return;
+}
+
+// TODO race condition; fix waiting on https://crbug.com/478183
+chrome.runtime.sendMessage({
+  type: "checkDNT"
+}, function (enabled) {
+  if (enabled) {
+    window.injectScript(getPageScript());
+  }
+});
+
+}());
diff --git a/src/js/contentscripts/fingerprinting.js b/src/js/contentscripts/fingerprinting.js
new file mode 100644
index 0000000..0891896
--- /dev/null
+++ b/src/js/contentscripts/fingerprinting.js
@@ -0,0 +1,367 @@
+/*
+ * This file is part of Privacy Badger <https://www.eff.org/privacybadger>
+ * Copyright (C) 2015 Electronic Frontier Foundation
+ *
+ * Derived from Chameleon <https://github.com/ghostwords/chameleon>
+ * Copyright (C) 2015 ghostwords
+ *
+ * Privacy Badger is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Privacy Badger is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Privacy Badger.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+function getFpPageScript() {
+
+  // code below is not a content script: no chrome.* APIs /////////////////////
+
+  // return a string
+  return "(" + function (DOCUMENT, dispatchEvent, CUSTOM_EVENT, ERROR, DATE, setTimeout, OBJECT) {
+
+    const V8_STACK_TRACE_API = !!(ERROR && ERROR.captureStackTrace);
+
+    if (V8_STACK_TRACE_API) {
+      ERROR.stackTraceLimit = Infinity; // collect all frames
+    } else {
+      // from https://github.com/csnover/TraceKit/blob/b76ad786f84ed0c94701c83d8963458a8da54d57/tracekit.js#L641
+      var geckoCallSiteRe = /^\s*(.*?)(?:\((.*?)\))?@?((?:file|https?|chrome):.*?):(\d+)(?::(\d+))?\s*$/i;
+    }
+
+    var event_id = DOCUMENT.currentScript.getAttribute('data-event-id');
+
+    // from Underscore v1.6.0
+    function debounce(func, wait, immediate) {
+      var timeout, args, context, timestamp, result;
+
+      var later = function () {
+        var last = DATE.now() - timestamp;
+        if (last < wait) {
+          timeout = setTimeout(later, wait - last);
+        } else {
+          timeout = null;
+          if (!immediate) {
+            result = func.apply(context, args);
+            context = args = null;
+          }
+        }
+      };
+
+      return function () {
+        context = this; // eslint-disable-line consistent-this
+        args = arguments;
+        timestamp = DATE.now();
+        var callNow = immediate && !timeout;
+        if (!timeout) {
+          timeout = setTimeout(later, wait);
+        }
+        if (callNow) {
+          result = func.apply(context, args);
+          context = args = null;
+        }
+
+        return result;
+      };
+    }
+
+    // messages the injected script
+    var send = (function () {
+      var messages = [];
+
+      // debounce sending queued messages
+      var _send = debounce(function () {
+        dispatchEvent.call(DOCUMENT, new CUSTOM_EVENT(event_id, {
+          detail: messages
+        }));
+
+        // clear the queue
+        messages = [];
+      }, 100);
+
+      return function (msg) {
+        // queue the message
+        messages.push(msg);
+
+        _send();
+      };
+    }());
+
+    /**
+     * Gets the stack trace by throwing and catching an exception.
+     * @returns {*} Returns the stack trace
+     */
+    function getStackTraceFirefox() {
+      let stack;
+
+      try {
+        throw new ERROR();
+      } catch (err) {
+        stack = err.stack;
+      }
+
+      return stack.split('\n');
+    }
+
+    /**
+     * Gets the stack trace using the V8 stack trace API:
+     * https://github.com/v8/v8/wiki/Stack-Trace-API
+     * @returns {*} Returns the stack trace
+     */
+    function getStackTrace() {
+      let err = {},
+        origFormatter,
+        stack;
+
+      origFormatter = ERROR.prepareStackTrace;
+      ERROR.prepareStackTrace = function (_, structuredStackTrace) {
+        return structuredStackTrace;
+      };
+
+      ERROR.captureStackTrace(err, getStackTrace);
+      stack = err.stack;
+
+      ERROR.prepareStackTrace = origFormatter;
+
+      return stack;
+    }
+
+    /**
+     * Strip away the line and column number (from stack trace urls)
+     * @param script_url The stack trace url to strip
+     * @returns {String} the pure URL
+     */
+    function stripLineAndColumnNumbers(script_url) {
+      return script_url.replace(/:\d+:\d+$/, '');
+    }
+
+    /**
+     * Parses the stack trace for the originating script URL
+     * without using the V8 stack trace API.
+     * @returns {String} The URL of the originating script
+     */
+    function getOriginatingScriptUrlFirefox() {
+      let trace = getStackTraceFirefox();
+
+      if (trace.length < 4) {
+        return '';
+      }
+
+      // this script is at 0, 1 and 2
+      let callSite = trace[3];
+
+      let scriptUrlMatches = callSite.match(geckoCallSiteRe);
+      return scriptUrlMatches && scriptUrlMatches[3] || '';
+    }
+
+    /**
+     * Parses the stack trace for the originating script URL.
+     * @returns {String} The URL of the originating script
+     */
+    function getOriginatingScriptUrl() {
+      let trace = getStackTrace();
+
+      if (OBJECT.prototype.toString.call(trace) == '[object String]') {
+        // we failed to get a structured stack trace
+        trace = trace.split('\n');
+        // this script is at 0, 1, 2 and 3
+        let script_url_matches = trace[4].match(/\((http.*:\d+:\d+)/);
+        // TODO do we need stripLineAndColumnNumbers (in both places) here?
+        return script_url_matches && stripLineAndColumnNumbers(script_url_matches[1]) || stripLineAndColumnNumbers(trace[4]);
+      }
+
+      if (trace.length < 2) {
+        return '';
+      }
+
+      // this script is at 0 and 1
+      let callSite = trace[2];
+
+      if (callSite.isEval()) {
+        // argh, getEvalOrigin returns a string ...
+        let eval_origin = callSite.getEvalOrigin(),
+          script_url_matches = eval_origin.match(/\((http.*:\d+:\d+)/);
+
+        // TODO do we need stripLineAndColumnNumbers (in both places) here?
+        return script_url_matches && stripLineAndColumnNumbers(script_url_matches[1]) || stripLineAndColumnNumbers(eval_origin);
+      } else {
+        return callSite.getFileName();
+      }
+    }
+
+    /**
+     * Monitor the writes in a canvas instance
+     * @param item special item objects
+     */
+    function trapInstanceMethod(item) {
+      var is_canvas_write = (
+        item.propName == 'fillText' || item.propName == 'strokeText'
+      );
+
+      item.obj[item.propName] = (function (orig) {
+        // set to true after the first write, if the method is not
+        // restorable. Happens if another library also overwrites
+        // this method.
+        var skip_monitoring = false;
+
+        function wrapped() {
+          var args = arguments;
+
+          if (is_canvas_write) {
+            // to avoid false positives,
+            // bail if the text being written is too short,
+            // of if we've already sent a monitoring payload
+            if (skip_monitoring || !args[0] || args[0].length < 5) {
+              return orig.apply(this, args);
+            }
+          }
+
+          var script_url = (
+              V8_STACK_TRACE_API ?
+                getOriginatingScriptUrl() :
+                getOriginatingScriptUrlFirefox()
+            ),
+            msg = {
+              obj: item.objName,
+              prop: item.propName,
+              scriptUrl: script_url
+            };
+
+          if (item.hasOwnProperty('extra')) {
+            msg.extra = item.extra.apply(this, args);
+          }
+
+          send(msg);
+
+          if (is_canvas_write) {
+            // optimization: one canvas write is enough,
+            // restore original write method
+            // to this CanvasRenderingContext2D object instance
+            // Careful! Only restorable if we haven't already been replaced
+            // by another lib, such as the hidpi polyfill
+            if (this[item.propName] === wrapped) {
+              this[item.propName] = orig;
+            } else {
+              skip_monitoring = true;
+            }
+          }
+
+          return orig.apply(this, args);
+        }
+
+        OBJECT.defineProperty(wrapped, "name", { value: orig.name });
+        OBJECT.defineProperty(wrapped, "length", { value: orig.length });
+        OBJECT.defineProperty(wrapped, "toString", { value: orig.toString.bind(orig) });
+
+        return wrapped;
+
+      }(item.obj[item.propName]));
+    }
+
+    var methods = [];
+
+    ['getImageData', 'fillText', 'strokeText'].forEach(function (method) {
+      var item = {
+        objName: 'CanvasRenderingContext2D.prototype',
+        propName: method,
+        obj: CanvasRenderingContext2D.prototype,
+        extra: function () {
+          return {
+            canvas: true
+          };
+        }
+      };
+
+      if (method == 'getImageData') {
+        item.extra = function () {
+          var args = arguments,
+            width = args[2],
+            height = args[3];
+
+          // "this" is a CanvasRenderingContext2D object
+          if (width === undefined) {
+            width = this.canvas.width;
+          }
+          if (height === undefined) {
+            height = this.canvas.height;
+          }
+
+          return {
+            canvas: true,
+            width: width,
+            height: height
+          };
+        };
+      }
+
+      methods.push(item);
+    });
+
+    methods.push({
+      objName: 'HTMLCanvasElement.prototype',
+      propName: 'toDataURL',
+      obj: HTMLCanvasElement.prototype,
+      extra: function () {
+        // "this" is a canvas element
+        return {
+          canvas: true,
+          width: this.width,
+          height: this.height
+        };
+      }
+    });
+
+    methods.forEach(trapInstanceMethod);
+
+  // save locally to keep from getting overwritten by site code
+  } + "(document, document.dispatchEvent, CustomEvent, Error, Date, setTimeout, Object));";
+
+  // code above is not a content script: no chrome.* APIs /////////////////////
+
+}
+
+// END FUNCTION DEFINITIONS ///////////////////////////////////////////////////
+
+(function () {
+
+// don't inject into non-HTML documents (such as XML documents)
+// but do inject into XHTML documents
+if (document instanceof HTMLDocument === false && (
+  document instanceof XMLDocument === false ||
+  document.createElement('div') instanceof HTMLDivElement === false
+)) {
+  return;
+}
+
+// TODO race condition; fix waiting on https://crbug.com/478183
+chrome.runtime.sendMessage({
+  type: "detectFingerprinting"
+}, function (enabled) {
+  if (!enabled) {
+    return;
+  }
+  /**
+   * Communicating to webrequest.js
+   */
+  var event_id = Math.random();
+
+  // listen for messages from the script we are about to insert
+  document.addEventListener(event_id, function (e) {
+    // pass these on to the background page
+    chrome.runtime.sendMessage({
+      type: "fpReport",
+      data: e.detail
+    });
+  });
+
+  window.injectScript(getFpPageScript(), {
+    event_id: event_id
+  });
+});
+
+}());
diff --git a/src/js/contentscripts/socialwidgets.js b/src/js/contentscripts/socialwidgets.js
new file mode 100644
index 0000000..14ae2b3
--- /dev/null
+++ b/src/js/contentscripts/socialwidgets.js
@@ -0,0 +1,641 @@
+/*
+ * This file is part of Privacy Badger <https://www.eff.org/privacybadger>
+ * Copyright (C) 2014 Electronic Frontier Foundation
+ * Derived from ShareMeNot
+ * Copyright (C) 2011-2014 University of Washington
+ *
+ * Privacy Badger is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Privacy Badger is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Privacy Badger.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * ShareMeNot is licensed under the MIT license:
+ * http://www.opensource.org/licenses/mit-license.php
+ *
+ * Copyright (c) 2011-2014 University of Washington
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+// widget data
+let widgetList;
+
+// cached chrome.i18n.getMessage() results
+const TRANSLATIONS = {};
+
+// references to widget page elements
+const WIDGET_ELS = {};
+
+
+/**
+ * @param {Object} response response to checkWidgetReplacementEnabled
+ */
+function initialize(response) {
+  for (const key in response.translations) {
+    TRANSLATIONS[key] = response.translations[key];
+  }
+
+  widgetList = response.widgetList;
+
+  // check for widgets blocked before we got here
+  replaceInitialTrackerButtonsHelper(response.widgetsToReplace);
+
+  // set up listener for dynamically created widgets
+  chrome.runtime.onMessage.addListener(function (request) {
+    if (request.replaceWidget) {
+      replaceSubsequentTrackerButtonsHelper(request.trackerDomain);
+    }
+  });
+}
+
+/**
+ * Creates a replacement placeholder element for the given widget.
+ *
+ * @param {Object} widget the SocialWidget object
+ * @param {Element} trackerElem the button/widget element we are replacing
+ * @param {Function} callback called with the replacement element
+ */
+function createReplacementElement(widget, trackerElem, callback) {
+  let buttonData = widget.replacementButton;
+
+  // no image data to fetch
+  if (!buttonData.hasOwnProperty('imagePath')) {
+    return setTimeout(function () {
+      _createReplacementElementCallback(widget, trackerElem, callback);
+    }, 0);
+  }
+
+  // already have replacement button image URI cached
+  if (buttonData.buttonUrl) {
+    return setTimeout(function () {
+      _createReplacementElementCallback(widget, trackerElem, callback);
+    }, 0);
+  }
+
+  // already messaged for but haven't yet received the image data
+  if (buttonData.loading) {
+    // check back in 10 ms
+    return setTimeout(function () {
+      createReplacementElement(widget, trackerElem, callback);
+    }, 10);
+  }
+
+  // don't have image data cached yet, get it from the background page
+  buttonData.loading = true;
+  chrome.runtime.sendMessage({
+    type: "getReplacementButton",
+    widgetName: widget.name
+  }, function (response) {
+    if (response) {
+      buttonData.buttonUrl = response; // cache image data
+      _createReplacementElementCallback(widget, trackerElem, callback);
+    }
+  });
+}
+
+function _createReplacementElementCallback(widget, trackerElem, callback) {
+  if (widget.replacementButton.buttonUrl) {
+    _createButtonReplacement(widget, callback);
+  } else {
+    _createWidgetReplacement(widget, trackerElem, callback);
+  }
+}
+
+function _createButtonReplacement(widget, callback) {
+  let buttonData = widget.replacementButton,
+    button_type = buttonData.type;
+
+  let button = document.createElement("img");
+  button.setAttribute("src", buttonData.buttonUrl);
+
+  // TODO use custom tooltip to support RTL locales?
+  button.setAttribute(
+    "title",
+    TRANSLATIONS.social_tooltip_pb_has_replaced.replace("XXX", widget.name)
+  );
+
+  let styleAttrs = [
+    "border: none",
+    "cursor: pointer",
+    "height: auto",
+    "width: auto",
+  ];
+  button.setAttribute("style", styleAttrs.join(" !important;") + " !important");
+
+  // normal button type; just open a new window when clicked
+  if (button_type === 0) {
+    let popup_url = buttonData.details + encodeURIComponent(window.location.href);
+
+    button.addEventListener("click", function () {
+      window.open(popup_url);
+    });
+
+  // in place button type; replace the existing button
+  // with an iframe when clicked
+  } else if (button_type == 1) {
+    let iframe_url = buttonData.details + encodeURIComponent(window.location.href);
+
+    button.addEventListener("click", function () {
+      replaceButtonWithIframeAndUnblockTracker(button, widget.name, iframe_url);
+    }, { once: true });
+
+  // in place button type; replace the existing button with code
+  // specified in the widgets JSON
+  } else if (button_type == 2) {
+    button.addEventListener("click", function () {
+      replaceButtonWithHtmlCodeAndUnblockTracker(button, widget.name, buttonData.details);
+    }, { once: true });
+  }
+
+  callback(button);
+}
+
+function _createWidgetReplacement(widget, trackerElem, callback) {
+  let replacementEl;
+
+  // in-place widget type:
+  // reinitialize the widget by reinserting its element's HTML
+  if (widget.replacementButton.type == 3) {
+    replacementEl = createReplacementWidget(
+      widget, trackerElem, reinitializeWidgetAndUnblockTracker);
+
+  // in-place widget type:
+  // reinitialize the widget by reinserting its element's HTML
+  // and activating associated scripts
+  } else if (widget.replacementButton.type == 4) {
+    let activationFn = replaceWidgetAndReloadScripts;
+
+    // if there are no matching script elements
+    if (!document.querySelectorAll(widget.scriptSelectors.join(',')).length) {
+      // and we don't have a fallback script URL
+      if (!widget.fallbackScriptUrl) {
+        // we can't do "in-place" activation; reload the page instead
+        activationFn = function () {
+          unblockTracker(widget.name, function () {
+            location.reload();
+          });
+        };
+      }
+    }
+
+    replacementEl = createReplacementWidget(widget, trackerElem, activationFn);
+  }
+
+  callback(replacementEl);
+}
+
+/**
+ * Unblocks the given widget and replaces the given button with an iframe
+ * pointing to the given URL.
+ *
+ * @param {Element} button the DOM element of the button to replace
+ * @param {String} widget_name the name of the replacement widget
+ * @param {String} iframeUrl the URL of the iframe to replace the button
+ */
+function replaceButtonWithIframeAndUnblockTracker(button, widget_name, iframeUrl) {
+  unblockTracker(widget_name, function () {
+    // check is needed as for an unknown reason this callback function is
+    // executed for buttons that have already been removed; we are trying
+    // to prevent replacing an already removed button
+    if (button.parentNode !== null) {
+      let iframe = document.createElement("iframe");
+
+      iframe.setAttribute("src", iframeUrl);
+      iframe.setAttribute("style", "border: none !important; height: 1.5em !important;");
+
+      button.parentNode.replaceChild(iframe, button);
+    }
+  });
+}
+
+/**
+ * Unblocks the given widget and replaces the given button with the
+ * HTML code defined in the provided SocialWidget object.
+ *
+ * @param {Element} button the DOM element of the button to replace
+ * @param {String} widget_name the name of the replacement widget
+ * @param {String} html the HTML string that should replace the button
+ */
+function replaceButtonWithHtmlCodeAndUnblockTracker(button, widget_name, html) {
+  unblockTracker(widget_name, function () {
+    // check is needed as for an unknown reason this callback function is
+    // executed for buttons that have already been removed; we are trying
+    // to prevent replacing an already removed button
+    if (button.parentNode !== null) {
+      let codeContainer = document.createElement("div");
+      codeContainer.innerHTML = html;
+
+      button.parentNode.replaceChild(codeContainer, button);
+
+      replaceScriptsRecurse(codeContainer);
+    }
+  });
+}
+
+/**
+ * Unblocks the given widget and replaces our replacement placeholder
+ * with the original third-party widget element.
+ *
+ * The teardown to the initialization defined in createReplacementWidget().
+ *
+ * @param {String} name the name/type of this widget (SoundCloud, Vimeo etc.)
+ */
+function reinitializeWidgetAndUnblockTracker(name) {
+  unblockTracker(name, function () {
+    // restore all widgets of this type
+    WIDGET_ELS[name].forEach(data => {
+      data.parent.replaceChild(data.widget, data.replacement);
+    });
+    WIDGET_ELS[name] = [];
+  });
+}
+
+/**
+ * Similar to reinitializeWidgetAndUnblockTracker() above,
+ * but also reruns scripts defined in scriptSelectors.
+ *
+ * @param {String} name the name/type of this widget (Disqus, Google reCAPTCHA)
+ */
+function replaceWidgetAndReloadScripts(name) {
+  unblockTracker(name, function () {
+    // restore all widgets of this type
+    WIDGET_ELS[name].forEach(data => {
+      data.parent.replaceChild(data.widget, data.replacement);
+      reloadScripts(data.scriptSelectors, data.fallbackScriptUrl);
+    });
+    WIDGET_ELS[name] = [];
+  });
+}
+
+/**
+ * Find and replace script elements with their copies to trigger re-running.
+ */
+function reloadScripts(selectors, fallback_script_url) {
+  let scripts = document.querySelectorAll(selectors.join(','));
+
+  // if there are no matches, try a known script URL
+  if (!scripts.length && fallback_script_url) {
+    let parent = document.documentElement,
+      replacement = document.createElement("script");
+    replacement.src = fallback_script_url;
+    parent.insertBefore(replacement, parent.firstChild);
+    return;
+  }
+
+  for (let scriptEl of scripts) {
+    // reinsert script elements only
+    if (!scriptEl.nodeName || scriptEl.nodeName.toLowerCase() != 'script') {
+      continue;
+    }
+
+    let replacement = document.createElement("script");
+    for (let attr of scriptEl.attributes) {
+      replacement.setAttribute(attr.nodeName, attr.value);
+    }
+    scriptEl.parentNode.replaceChild(replacement, scriptEl);
+    // reinsert one script and quit
+    break;
+  }
+}
+
+/**
+ * Dumping scripts into innerHTML won't execute them, so replace them
+ * with executable scripts.
+ */
+function replaceScriptsRecurse(node) {
+  if (node.nodeName && node.nodeName.toLowerCase() == 'script' &&
+      node.getAttribute && node.getAttribute("type") == "text/javascript") {
+    let script = document.createElement("script");
+    script.text = node.innerHTML;
+    script.src = node.src;
+    node.parentNode.replaceChild(script, node);
+  } else {
+    let i = 0,
+      children = node.childNodes;
+    while (i < children.length) {
+      replaceScriptsRecurse(children[i]);
+      i++;
+    }
+  }
+  return node;
+}
+
+
+/**
+ * Replaces all tracker buttons on the current web page with the internal
+ * replacement buttons, respecting the user's blocking settings.
+ *
+ * @param {Array} widgetsToReplace a list of widget names to replace
+ */
+function replaceInitialTrackerButtonsHelper(widgetsToReplace) {
+  widgetList.forEach(function (widget) {
+    if (widgetsToReplace.hasOwnProperty(widget.name)) {
+      replaceIndividualButton(widget);
+    }
+  });
+}
+
+/**
+ * Individually replaces tracker buttons blocked after initial check.
+ */
+function replaceSubsequentTrackerButtonsHelper(tracker_domain) {
+  if (!widgetList) {
+    return;
+  }
+  widgetList.forEach(function (widget) {
+    let replace = widget.domains.some(domain => {
+      if (domain == tracker_domain) {
+        return true;
+      // leading wildcard
+      } else if (domain[0] == "*") {
+        if (tracker_domain.endsWith(domain.slice(1))) {
+          return true;
+        }
+      }
+      return false;
+    });
+    if (replace) {
+      replaceIndividualButton(widget);
+    }
+  });
+}
+
+function _make_id(prefix) {
+  return prefix + "-" + Math.random().toString().replace(".", "");
+}
+
+function createReplacementWidget(widget, elToReplace, activationFn) {
+  let name = widget.name;
+
+  let widgetFrame = document.createElement('iframe');
+
+  // widget replacement frame styles
+  let border_width = 1;
+  let styleAttrs = [
+    "background-color: #fff",
+    "border: " + border_width + "px solid #ec9329",
+    "min-width: 220px",
+    "min-height: 210px",
+    "max-height: 600px",
+    "z-index: 2147483647",
+  ];
+  if (elToReplace.offsetWidth > 0) {
+    styleAttrs.push(`width: ${elToReplace.offsetWidth - 2*border_width}px`);
+  }
+  if (elToReplace.offsetHeight > 0) {
+    styleAttrs.push(`height: ${elToReplace.offsetHeight - 2*border_width}px`);
+  }
+  widgetFrame.style = styleAttrs.join(" !important;") + " !important";
+
+  let widgetDiv = document.createElement('div');
+
+  // parent div styles
+  styleAttrs = [
+    "display: flex",
+    "flex-direction: column",
+    "align-items: center",
+    "justify-content: center",
+    "width: 100%",
+    "height: 100%",
+  ];
+  if (TRANSLATIONS.rtl) {
+    styleAttrs.push("direction: rtl");
+  }
+  widgetDiv.style = styleAttrs.join(" !important;") + " !important";
+
+  // child div styles
+  styleAttrs = [
+    "color: #303030",
+    "font-family: helvetica, arial, sans-serif",
+    "font-size: 16px",
+    "display: flex",
+    "flex-wrap: wrap",
+    "justify-content: center",
+    "text-align: center",
+    "margin: 10px",
+  ];
+
+  let textDiv = document.createElement('div');
+  textDiv.style = styleAttrs.join(" !important;") + " !important";
+  textDiv.appendChild(document.createTextNode(
+    TRANSLATIONS.widget_placeholder_pb_has_replaced.replace("XXX", name)));
+  let infoIcon = document.createElement('a'),
+    info_icon_id = _make_id("ico-help");
+  infoIcon.id = info_icon_id;
+  infoIcon.href = "https://privacybadger.org/#How-does-Privacy-Badger-handle-social-media-widgets";
+  infoIcon.rel = "noreferrer";
+  infoIcon.target = "_blank";
+  textDiv.appendChild(infoIcon);
+  widgetDiv.appendChild(textDiv);
+
+  let buttonDiv = document.createElement('div');
+  styleAttrs.push("width: 100%");
+  buttonDiv.style = styleAttrs.join(" !important;") + " !important";
+
+  // allow once button
+  let button = document.createElement('button'),
+    button_id = _make_id("btn-once");
+  button.id = button_id;
+  styleAttrs = [
+    "transition: background-color 0.25s ease-out, border-color 0.25s ease-out, color 0.25s ease-out",
+    "border-radius: 3px",
+    "cursor: pointer",
+    "font-family: 'Lucida Grande', 'Segoe UI', Tahoma, 'DejaVu Sans', Arial, sans-serif",
+    "font-size: 12px",
+    "font-weight: bold",
+    "line-height: 16px",
+    "padding: 10px",
+    "margin: 4px",
+    "text-align: center",
+    "width: 70%",
+    "max-width: 280px",
+  ];
+  button.style = styleAttrs.join(" !important;") + " !important";
+
+  // allow on this site button
+  let site_button = document.createElement('button'),
+    site_button_id = _make_id("btn-site");
+  site_button.id = site_button_id;
+  site_button.style = styleAttrs.join(" !important;") + " !important";
+
+  button.appendChild(document.createTextNode(TRANSLATIONS.allow_once));
+  site_button.appendChild(document.createTextNode(TRANSLATIONS.allow_on_site));
+
+  buttonDiv.appendChild(button);
+  buttonDiv.appendChild(site_button);
+
+  widgetDiv.appendChild(buttonDiv);
+
+  // save refs. to elements for use in teardown
+  if (!WIDGET_ELS.hasOwnProperty(name)) {
+    WIDGET_ELS[name] = [];
+  }
+  let data = {
+    parent: elToReplace.parentNode,
+    widget: elToReplace,
+    replacement: widgetFrame
+  };
+  if (widget.scriptSelectors) {
+    data.scriptSelectors = widget.scriptSelectors;
+    if (widget.fallbackScriptUrl) {
+      data.fallbackScriptUrl = widget.fallbackScriptUrl;
+    }
+  }
+  WIDGET_ELS[name].push(data);
+
+  // set up click handler
+  widgetFrame.addEventListener('load', function () {
+    let onceButton = widgetFrame.contentDocument.getElementById(button_id),
+      siteButton = widgetFrame.contentDocument.getElementById(site_button_id);
+
+    onceButton.addEventListener("click", function (e) {
+      e.preventDefault();
+      activationFn(name);
+    }, { once: true });
+
+    siteButton.addEventListener("click", function (e) {
+      e.preventDefault();
+
+      // first message the background page to record that
+      // this widget should always be allowed on this site
+      chrome.runtime.sendMessage({
+        type: "allowWidgetOnSite",
+        widgetName: name
+      }, function () {
+        activationFn(name);
+      });
+    }, { once: true });
+
+  }, false); // end of click handler
+
+  let head_styles = `
+html, body {
+  height: 100% !important;
+  overflow: hidden !important;
+}
+#${button_id} {
+  border: 2px solid #f06a0a !important;
+  background-color: #f06a0a !important;
+  color: #fefefe !important;
+}
+#${site_button_id} {
+  border: 2px solid #333 !important;
+  background-color: #fefefe !important;
+  color: #333 !important;
+}
+#${button_id}:hover {
+  background-color: #fefefe !important;
+  color: #333 !important;
+}
+#${site_button_id}:hover {
+  background-color: #fefefe !important;
+  border: 2px solid #f06a0a !important;
+}
+#${info_icon_id} {
+  position: absolute;
+  ${TRANSLATIONS.rtl ? "left" : "right"}: 4px;
+  top: 4px;
+  line-height: 12px;
+  text-decoration: none;
+}
+#${info_icon_id}:before {
+  border: 2px solid;
+  border-radius: 50%;
+  display: inline-block;
+  color: #555;
+  content: '?';
+  font-size: 12px;
+  font-weight: bold;
+  padding: 1px;
+  height: 1em;
+  width: 1em;
+}
+#${info_icon_id}:hover:before {
+  color: #ec9329;
+}
+  `.trim();
+
+  widgetFrame.srcdoc = '<html><head><style>' + head_styles + '</style></head><body style="margin:0">' + widgetDiv.outerHTML + '</body></html>';
+
+  return widgetFrame;
+}
+
+/**
+ * Replaces buttons/widgets in the DOM.
+ */
+function replaceIndividualButton(widget) {
+  let selector = widget.buttonSelectors.join(','),
+    elsToReplace = document.querySelectorAll(selector);
+
+  elsToReplace.forEach(function (el) {
+    createReplacementElement(widget, el, function (replacementEl) {
+      el.parentNode.replaceChild(replacementEl, el);
+    });
+  });
+}
+
+/**
+ * Messages the background page to temporarily allow domains associated with a
+ * given replacement widget.
+ * Calls the provided callback function upon response.
+ *
+ * @param {String} name the name of the replacement widget
+ * @param {Function} callback the callback function
+ */
+function unblockTracker(name, callback) {
+  let request = {
+    type: "unblockWidget",
+    widgetName: name
+  };
+  chrome.runtime.sendMessage(request, callback);
+}
+
+// END FUNCTION DEFINITIONS ///////////////////////////////////////////////////
+
+(function () {
+
+// don't inject into non-HTML documents (such as XML documents)
+// but do inject into XHTML documents
+if (document instanceof HTMLDocument === false && (
+  document instanceof XMLDocument === false ||
+  document.createElement('div') instanceof HTMLDivElement === false
+)) {
+  return;
+}
+
+chrome.runtime.sendMessage({
+  type: "checkWidgetReplacementEnabled"
+}, function (response) {
+  if (!response) {
+    return;
+  }
+  initialize(response);
+});
+
+}());
diff --git a/src/js/contentscripts/supercookie.js b/src/js/contentscripts/supercookie.js
new file mode 100644
index 0000000..0b15211
--- /dev/null
+++ b/src/js/contentscripts/supercookie.js
@@ -0,0 +1,151 @@
+/*
+ * This file is part of Privacy Badger <https://www.eff.org/privacybadger>
+ * Copyright (C) 2015 Electronic Frontier Foundation
+ *
+ * Derived from Chameleon <https://github.com/ghostwords/chameleon>
+ * Copyright (C) 2015 ghostwords
+ *
+ * Privacy Badger is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Privacy Badger is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Privacy Badger.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Generate script to inject into the page
+ *
+ * @returns {string}
+ */
+function getScPageScript() {
+  // code below is not a content script: no chrome.* APIs /////////////////////
+
+  // return a string
+  return "(" + function () {
+
+    /*
+     * If localStorage is inaccessible, such as when "Block third-party cookies"
+     * in enabled in Chrome or when `dom.storage.enabled` is set to `false` in
+     * Firefox, do not go any further.
+     */
+    try {
+      // No localStorage raises an Exception in Chromium-based browsers, while
+      // it's equal to `null` in Firefox.
+      if (null === localStorage) {
+        throw false;
+      }
+    } catch (ex) {
+      return;
+    }
+
+    (function (DOCUMENT, dispatchEvent, CUSTOM_EVENT, LOCAL_STORAGE, OBJECT, keys) {
+
+      var event_id = DOCUMENT.currentScript.getAttribute('data-event-id-super-cookie');
+
+      /**
+       * send message to the content script
+       *
+       * @param {*} message
+       */
+      var send = function (message) {
+        dispatchEvent.call(DOCUMENT, new CUSTOM_EVENT(event_id, {
+          detail: message
+        }));
+      };
+
+      /**
+       * Read HTML5 local storage and return contents
+       * @returns {Object}
+       */
+      let getLocalStorageItems = function () {
+        let lsItems = {};
+        for (let i = 0; i < LOCAL_STORAGE.length; i++) {
+          let key = LOCAL_STORAGE.key(i);
+          lsItems[key] = LOCAL_STORAGE.getItem(key);
+        }
+        return lsItems;
+      };
+
+      if (event_id) { // inserted script may run before the event_id is available
+        let localStorageItems = getLocalStorageItems();
+        if (keys.call(OBJECT, localStorageItems).length) {
+          // send to content script
+          send({ localStorageItems });
+        }
+      }
+
+    // save locally to keep from getting overwritten by site code
+    } (document, document.dispatchEvent, CustomEvent, localStorage, Object, Object.keys));
+
+  } + "());";
+
+  // code above is not a content script: no chrome.* APIs /////////////////////
+
+}
+
+// END FUNCTION DEFINITIONS ///////////////////////////////////////////////////
+
+(function () {
+
+// don't inject into non-HTML documents (such as XML documents)
+// but do inject into XHTML documents
+if (document instanceof HTMLDocument === false && (
+  document instanceof XMLDocument === false ||
+  document.createElement('div') instanceof HTMLDivElement === false
+)) {
+  return;
+}
+
+// don't bother asking to run when trivially in first-party context
+if (window.top == window) {
+  return;
+}
+
+// TODO race condition; fix waiting on https://crbug.com/478183
+
+// TODO here we could also be injected too quickly
+// and miss localStorage setting upon initial page load
+//
+// we should eventually switch injection back to document_start
+// (reverting https://github.com/EFForg/privacybadger/pull/1522),
+// and fix localstorage detection
+// (such as by delaying it or peforming it periodically)
+//
+// could then remove test workarounds like
+// https://github.com/EFForg/privacybadger/commit/39d5d0899e22d1c451d429e44553c5f9cad7fc46
+
+// TODO sometimes contentscripts/utils.js isn't here?!
+// TODO window.FRAME_URL / window.injectScript are undefined ...
+chrome.runtime.sendMessage({
+  type: "inspectLocalStorage",
+  frameUrl: window.FRAME_URL
+}, function (enabledAndThirdParty) {
+  if (!enabledAndThirdParty) {
+    return;
+  }
+
+  var event_id_super_cookie = Math.random();
+
+  // listen for messages from the script we are about to insert
+  document.addEventListener(event_id_super_cookie, function (e) {
+    // pass these on to the background page (handled by webrequest.js)
+    chrome.runtime.sendMessage({
+      type: "supercookieReport",
+      data: e.detail,
+      frameUrl: window.FRAME_URL
+    });
+  });
+
+  window.injectScript(getScPageScript(), {
+    event_id_super_cookie: event_id_super_cookie
+  });
+
+});
+
+}());
diff --git a/src/js/contentscripts/utils.js b/src/js/contentscripts/utils.js
new file mode 100644
index 0000000..9f0a0fa
--- /dev/null
+++ b/src/js/contentscripts/utils.js
@@ -0,0 +1,53 @@
+/*
+ * This file is part of Privacy Badger <https://www.eff.org/privacybadger>
+ * Copyright (C) 2018 Electronic Frontier Foundation
+ *
+ * Privacy Badger is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Privacy Badger is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Privacy Badger.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Executes a script in the page's JavaScript context.
+ *
+ * @param {String} text The content of the script to insert.
+ * @param {Object} data Data attributes to set on the inserted script tag.
+ */
+window.injectScript = function (text, data) {
+  var parent = document.documentElement,
+    script = document.createElement('script');
+
+  script.text = text;
+  script.async = false;
+
+  for (var key in data) {
+    script.setAttribute('data-' + key.replace(/_/g, '-'), data[key]);
+  }
+
+  parent.insertBefore(script, parent.firstChild);
+  parent.removeChild(script);
+};
+
+function getFrameUrl() {
+  let url = document.location.href,
+    parentFrame = (document != window.top) && window.parent;
+  while (parentFrame && url && !url.startsWith("http")) {
+    try {
+      url = parentFrame.document.location.href;
+    } catch (ex) {
+      // ignore 'Blocked a frame with origin "..."
+      // from accessing a cross-origin frame.' exceptions
+    }
+    parentFrame = (parentFrame != window.top) && parentFrame.parent;
+  }
+  return url;
+}
+window.FRAME_URL = getFrameUrl();