Google click tracking

posted in: Privacy, Security | 0

One of my clients recently reported that their computer seemed to be running more slowly than normal while surfing the web.
On closer investigation the problem seemed only to be occurring while clicking on links from Google searches.

Even closer investigation revealed that Google uses a Javascript to dynamically attach a JavaScript to every link in the search results, so that when the user clicks on a link some JavaScript is run which sends data back to Google.

I remember a number of years ago the major search engines tried changing the links of the search results, so that each link was actually back to the search engine. The search engine then re-directed the user (invisibly) to the site they really wanted. However this made an obvious difference to the URL of the link and was often quite slow as it required the search engine in question to send a page back to the user with a meta refresh or other re-direct command to take the user to the site they actually wanted to see.

Consequentally this system seemed to be scrapped fairly soon after it was introduced.

However now, all the major search engine employ a more ingenious / devious way to track your every “click”

After the web page is loaded, a JavaScript amends all the links so add an onClick event, so that clicking on a link sends a detailed message back to the search engine e.g. Google or Bing, as well as taking you to the URL in question.

In the case of my client, the JavaScript on their machine was running slowly for some reason, and the act of sending the click data to Google was taking some time, and had become noticeable.

Apart from slowing things down there are obvious privacy concerns about how Google knows not only what you are searching for, but also which links you click on.
If you’re logged into Gmail or other Google services at the time, or if you haven’t cleared your cache since you last used Gmail etc, Google will be able to associate your browsing (clicking) with your Gmail account and will be able to accurately track your browsing.

Currently I’ve not found a good solution to this problem. A partial solution is to block the script that contains this code (using Adblock in Firefox)
The rule to block the script is

http://www.google.com.au/extern_js/f/*.js

Unfortunately this script seems to contain the code that operates the new images search, so that only one page of images is displayed.

I’ve seen postings which include a GreaseMonkey script which is supposed to just prevent the onClick even being added, however at the time of writing this script doesn’t seem to work.

There is also a Firefox plugin called CustomizeGoogle however its not clear if this works with the current version of Firefox – the Mozilla site seems to suggest it does not.

For the moment I’ll have to put up with enabling and disabling the AdBlock filter for the script when I need to do an image search!