text: chrome.webRequest.onBeforeRequest.addListener(
      function() {
          return {cancel: true};
      },
      {
          urls: ["*://*.doubleclick.net/*", "*://www.googleadservices.com/*", "*://*.taboola.com/*", "*://*.adzerk.net/*", "*://*.adroll.com"]
      },
      ["blocking"]
  );
  
  //This script was specially created for the Chrome browser. It will not work if loaded into any
  //other browser (eg. Firefox).
  