Site Opens 100 Tabs to Fool Web Trackers

John Lister's picture

Mozilla has designed a site that will open 100 tabs at once, quite likely crashing a web browser. It's meant as a creative way to show how web tracking works.

The stunt is based around cookies: small text files put onto a computer via the browser to customize an online session to a website. Third-party tracking cookies are then generated, which keep a record of the sites a user visits. This information is then used by ad servers to deliver targeted ads based on website history.

"Track THIS" works by opening 100 tabs selected to represent a particular type of web user. The idea is that there will be enough to noticeably change the ads the person sees online, though the effect will fade within a few days as the tracking cookies rebuild the profile of the sites the user actually chooses to visit from day to day.

Doomsday Prepper Simulator

Users have the option of trying four "profiles", namely "Hypebeast", "Filthy Rich", "Doomsday" and "Influencer". For example, the "Doomsday" option opens 100 tabs with sites that a doomsday prepper might visit. (Source:

As Mozilla notes, opening that many tabs at once will put a lot of stress on a browser. It recommends users save data or close out any important web tabs first, for example online document editing or web-based email services.

Stunt Promotes Browser Feature

Naturally, Mozilla has some self-interest in these tests - and along with it, and publicity it brings.

It's using the stunt to promote the built-in Enhanced Tracking Protection in the Firefox browser, which stops third-party cookies from tracking a user's online activity. It's an option that's now switched on by default for anyone who downloads and installs Firefox for the first time and will eventually be switched on for all users.

Existing users can switch it on now by going to the "Privacy & Security" section of the Firefox settings menu, then "Content Blocking", then choosing the "Custom" option, ticking the "Cookies" checkbox and selecting "Third-party trackers" from the drop-down menu. (Source:

What's Your Opinion?

Would you run the "Track THIS" experiment? Is it a useful way to highlight the issue? Should all browsers block third-party tracker cookies by default?

Rate this article: 
Average: 5 (7 votes)


matt_2058's picture

I don't need this to crash a browser. I just have to go to yahoo, USAToday, or a few other sites. They're so riddled with pop-ups and ads that it used to freeze or crash my browser. Yeah, I could probably change a few settings, but then I give the sites control and I end up with a gazillion pop-ups trying to read a single paragraph. So I don't visit those anymore.

Every time my wife has a problem with a browser, it's yahoo or yahoo search. She can't seem to help herself.

Often heard at our home, "The internet is not broken, use google or something else."

Focused100's picture

Dennis I'd be interested in your take on this