I’ve been reading Eli Pariser’s book The Filter Bubble and was fascinated by his description of how data collection companies operate. Independently of that, David Ascher suggested that I add a feature to the Hackasaurus goggles which helps learners understand how cookies and tracking works.

I actually didn’t know a lot about tracking myself, so I whipped up a Firefox add-on called Collusion to help me visualize it better. The results were a little unsettling.

I’ve put a demonstration up at, which takes you through five popular websites and visualizes the data collection companies that track you across them. From there, you can download the add-on if you want to see the tracking visualization of your own browsing behavior evolve in real-time.

Special thanks to the Mozilla Add-on SDK team for making a great foundation to build on. This experiment also gave me a chance to play around with d3.js, which is a fantastic successor to Protovis. And thanks to PrivacyChoice for their excellent tracker list, which I’m sort of using without their permission. I hope that is okay.

I’m also not really a privacy expert, so I’m not sure if everything I say in the demonstration is completely true. If you find any inaccuracies, please let me know.

Finally, if you need the source code, it’s all at I’m particularly interested in seeing better visualizations than the force-directed graph I’m using, which regrettably requires a lot of user interaction to explore and understand.

38 Replies to “Collusion”

  1. Don’t forget about all those fancy like buttons and analytics thingees and social comment systems. Great visualization, this is important stuff to realize. We’re all big bags of meat with credit cards to these companies.

  2. what i fail to understand is how can extensive tracking of my web activities harm me in any way? doubleclick knows i frequent sites a, b, and c. big deal. and in return it gives me better ads. i really don’t see any reason for alarm.

  3. Great tool, shocking results.

    May be a slightly different treatment of the domain names would make even more clear.
    Currently sdomain names postfixed with or are heaped into a single one.

  4. I would love to see a Chrome version of this extension! Visualizations are key for teaching these kinds of concepts, great work.

  5. Yes, I have followed the link and installed the add on in my Firefox. Now what? What am I supposed to DO to see whatever it is I am supposed to see?????

  6. Sorry, it is very unclear what collusion actually does. If I use Ghostery or other addons, what does Collusion actually display? It is vague to say that Collusion shows “entities that track your behavior across the web”. Does Collusion display these entities even if a user has cookies or javascript disabled? So please put in your description: Does Collusion display entities that are are attempting to track you or entities that are actually receiving information about you (the latter is more useful). Thank you.

  7. Nice, but

    A) pleaase support FF 3.6 – at least as long the annoying memory leaks are still in newer FF versions

    B) please not only visualize, but also BLOCK them!


  8. Edit your “hosts file” (Windows, Linux, Mac) to redirect the tracking domain names to and you are done… without installing any add-on.

    As a bonus, you will surf faster since most adds will be blocked.

  9. Thanks anon, appreciate the suggestion. It looks pretty easy to edit the hosts file. For OS X there is an application called NetInfo Manager. My questions are: 1) where do I obtain a list of tracking domain names and 2) how do I keep this list current? Thanks!

  10. For those of us less technically inclined, some instructions on how to use the tool would be helpful. I installed the add-on but have no idea how to see the visualization.

  11. Thanks, nice stuff ๐Ÿ™‚

    After using collusion for about half an hour I decided that it’s high time to put Google and Facebook on a diet (using a couple of ABE user rules). This together with “keep cookies until I close FF” and with the Flash cookies conveniently located on a RAM disk should help to increase the “new user” count on most web sites ๐Ÿ™‚

    Btw: for some reason is the centre of all the otherwise tidily disjunct subnets, and thus is emulating Doubleclick. Is there anything I can do about that ?

  12. Actually this was a question, forgot question mark.
    So, any chance your add-on could work for opera, too?

  13. Reminds me of TheyRule…but very slick, initial impression was that the animation should be a little quicker.

  14. Doesn’t seem to work for me but then again with privoxy + ghostery, who know where to start with, when solving the issue with this product , trying it out to see whats what.

    P.S does this product rely on the various cookies and the a likes ?

  15. Hi, I got the add-on and was really perversely enjoying how huge my little net was getting. Cool visual. I’m not sure what if anything I am going to do about this information, but I like having it. I also posted your ad-on and a like to your site on my facebook.

    So, now I have a problem though. I have rebooted a few times and the thing just started weaving its web again, but this reboot I now have this message on the linked page:

    Since you don’t seem to have the Collusion Firefox Add-on installed … etc”

    but I do!

    What happened?

  16. I’m very interested in the answer to Gerts question:
    Why is also appearing in this graph?
    Could you please answer this question?


  17. Excellent tool. Even marketing people need to know how this works, and the impact and persistence across the interwebs, to help us make good decisions for our customers. If we’re uncomfortable with it, it’s not a good idea for them either. Thank you for this.

  18. This is an awesome add-on! I’ve known about such tracking for a while, but the visualization makes it really stand out. Have you given any thought to making a similar add-on for chrome? It would be very much appreciated if you were to do so. I haven’t been able to find any similar projects in the “chrome web store” that can compete with what I’ve seen you do for firefox. Thanks again!

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  20. Umm.. it seems that this plugin is actually saving my cookies when I explicitly remove all of them (clear @ end of session). If I clear all cookies, then look @ collusion’s graph, everything that was tracking me prior to the clear all is back in my list of cookies.

    I uninstalled collusion and cleared all and it now stays that way between start/quit of firefox sessions..

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