The latest beta version of Firefox 4 introduces lots of bug fixes and other improvements, but most importantly, it introduces Mozilla’s new opt-out mechanism for ad tracking. What this feature does is add a message to the commands your browser send to the web server when it requests pages that lets the server know that users do not want to be tracked.
Mozilla hopes to turn its system into a web-wide standard for those users who would prefer not to be tracked by advertisers. As of now, this is only a test, however, and as far as we know, no advertisers have agreed to adhere to this system yet. Given this, Mozilla notes that “you won’t notice any difference in your browsing until sites and advertisers agree to respond to your preference.”
To turn this feature on, head for the “Advanced” tab in your Firefox preferences and look for the “Tell web sites I do not want to be tracked” option. The feature is strictly opt-in and hence turned off by default.
Last month, Google made a similar move by launching a do-not-track plugin for Chrome. For now, Google has not made this a default feature, though. Thanks to Google’s strong position in the advertising world, however, its mechanism already allows you to opt out of being tracked by over 50 different online advertising companies.