We all know we’re being tracked by different websites and services to deliver ads and get customer data, but almost no one knows to what extent. The Collusion Firefox add-on shows you exactly how many advertising sites track your browsing behavior across the web, and to be perfectly honest it’s both fascinating and worrying at the same time. The add-on allows you to visualize the legitimate sites (represented by grey circles) and tracking ones (red circles), with arrows signifying the direction of traffic. A jump from IMDB to the New York Times yields a total of five sites that get information from your cookies, and that’s just the beginning. After a few more jumps, screen is a jumbled mass of circles, with a majority of them being red. The end of the demonstration (if you don’t have Firefox installed and are viewing it through Google Chrome) shows you how to protect yourself from these sites by using TrackerBlock.