Earlier today Mozilla introduced Collusion, an add-on for the Firefox browser that shows you how companies are tracking you as you surf the Web. A cool visual demonstration of the software illustrates all the links that form as you crisscross just a few popular sites online, including IMDB, the New York Times and the Huffington Post. The software shows the connections between sites you visit and third-party tracking and advertising networks such as Doubleclick and Scorecard Research. It makes plain the invisible web that has been woven through the Web.
The software was created as a protoype by Atul Varma, who explained in a blog post that he "didn’t know a lot about tracking myself, so I whipped up a Firefox add-on called Collusion to help me visualize it better," he wrote. "The results were a little unsettling."
Collusion will help you understand how you're being tracked online, but it won't stop it from happening. For that, you can disable "third-party" cookies on your browser and install other add-ons such as TrackerBlock. A number of internet giants have also announced support for a "do not track" button, though that option may not become available until the end of the year.