November 01, 2011, 3:23 PM — Ever wonder exactly who’s following you across the Web? Well wonder no longer. A cool and somewhat frightening tool called Collusion can help you do it.
This free Firefox extension watches all the tracking cookies that get deposited on your computer by the Web sites you visit (and the ads that live on them), then connects the dots between them as you surf.
(If you don’t use Firefox -- or don’t want to install the extension, which appears to slow surfing a teensy bit -- you can watch a demo of it in action at the @Toolness site.)
Install the extension, click on the Collusion icon in the lower right hand corner of your browser, then surf the Net as you normally would. Collusion opens up a new browser page that shows each site and ad network and how they interconnect.
For fun, I installed Collusion and then visited, in order, Google News, ITworld, CNN, the New York Times, Fox News, NPR, and Facebook. Here’s how my tracking history looks:
The cookies that collect information about your browsing history – as determined by the folks at PrivacyChoice, a site that offers tools for opting out of Web tracking -- are marked in red. The gray dots may or may not collect info about you. The bigger the dot, the more sites that deploy that cookie.
In this graph, for example, the big red dot in the center represents Doubleclick. The list down the right hand side of the screen represents the other sites I’ve visited (or that have visited me by dropping cookies on my computer) that also share information with Doubleclick. Doubleclick then gathers up this information about me – or rather, my browser – and combines it with other information to create a profile that can be used to determine what ads to show me on other sites I visit.
What else this tracking information could be used for is the $30 billion dollar question – or about how much money Internet Ads will bring in this year. The fact that I visited CNN and the New York Times isn't very interesting to anyone, including me. Had I visited How2BuildABomb.com or IllegalPorn.org or How2HaveAnAffair.net, that might be a different story.
What do these networks really know about you and how could that information be used? That’s the topic for another TY4NS blog post, coming soon to a browser near you.