A new piece of software released this week by browser-maker Mozilla does something unique: it provides a real-time visualization of who is tracking your movements online.

The software is called “Collusion,” developed last year by Mozilla programmer Atul Varma, who became inspired to code the program after reading extensively about online privacy matters. It plugs into the Firefox browser and watches as websites and ad networks drop “cookies” into the browser during normal surfing.

“Each dot in the graph represents a website,” Alex Fowler, the global privacy lead at Mozilla, explained to Raw Story. “As you browse, some web sites cause requests to other third-party web sites (as part of the page you’re viewing). When cookies are sent to these third-party web sites, Collusion puts them both on the graph and draws a line between them. As you visit more and more sites, some of the third parties receive cookies from a wide range of sites. Some web sites also cause Firefox to send cookies to many third parties. These two situations will show up in Collusion as big dots with lots of lines.”