The Mozilla Foundation has released a new plugin for their Firefox web browser designed to show you how your web surfing is tracked and aggregated. Called Collusion, the plugin “allows you to see all the third parties that are tracking your movements across the Web.” It looks at the cookies that web sites send to your browser, and then shows, “in real time, how that data creates a spider-web of interaction between companies and other trackers.”
We tried out the plugin, and quickly noticed not only that many sites set several tracking cookies, but that there was “collusion” among some of them.
What happens is that different sites use the same “behavioral tracking sites,” and:
Because the same cookies were transmitted to the same advertisers when you visited both sites, those advertisers effectively track you across them.
The whole tracking issue has come to the forefront recently. The question of a “do not track” header was raised last year, and Google recently added a “do not track” feature to its Chrome browser, but web site support is spotty at best. (A Macworld article, What you need to know about Do Not Track gives some answers to common questions about this technology.)
This Firefox plugin gives you a good idea of how much your activity on the web is tracked, and therefore “monetized.” These tracking companies want to know which sites you visit, and how often, to serve ads they think will appeal to you. However, this means they keep records of your activity, which you may not like.
Intego Washing Machine was designed to help with such privacy issues, allowing you to edit and delete browser cookies, either manually or automatically according to a schedule. (For example, you could delete all your browser cookies every week, if you wish.) It also cleans out other files left behind by web browsers – such as cache files – that can fill up your hard disk, and slow down your Mac.
So be aware of exactly what this tracking involves. It’s up to you to decide whether you want to delete you cookies regularly to ensure that your browsing histories are not stored by marketing companies.