How Google’s Cookie Replacement Can Be Used to Track You

Removing cookies isn't the end

Key Takeaways

  • Google will stop using cookies to track your internet browsing habits.
  • It will track you using your own browser, instead.
  • Advertisers may find it even easier to recognize and track individual users.
stack of cookies and glass of milk
Christina Branco / Unsplash

Google plans to stop using cookies to track you across the internet, and is selling this as a way to protect your privacy on the web. But—surprise—it will make little difference, and could even make it easier for advertisers to identify you.

Third-party cookies are how Amazon places ads for items you were viewing onto non-Amazon sites. The ads can load Amazon's cookie, even when you’re not on the retail giant's website, and identify you as you. This same trick can be used to track you across the web and gather information on your browsing habits. Google will stop doing this, but that doesn’t mean you can’t be tracked. It just means the process will work differently, and—at first—be harder to block.

"Due to the smaller cohort of users compared to the whole internet, identifying one particular user within a cohort of, let’s say, one thousand users will be even easier," software engineer Peter Thaleikis told Lifewire via email. "Fewer unique identifiers are needed to achieve the same if the set of options is substantially smaller."

Cookies and FLoC

You can block third-party cookies right now by opening the preferences in your web browser and disabling them. This will only allow sites you visit to save cookies on your computer, meaning the site can remember you, and you won’t have to log in every time you visit.

Advertisers don't need to track individual consumers across the web to get the performance benefits of digital advertising.

Google’s cookie replacement is called FLoC, or Federated Learning of Cohorts. FLoC bundles you together with other users who share similar browsing habits. Advertisers can then use this bundled data to serve relevant ads. Instead of using cookies, your browser will track your behavior, and offer up an anonymized blob of data to be bundled up with similar blobs.

That sounds fine, right? You’re never personally tracked, and advertisers still get to serve relevant ads. But not so fast; by combining FLoC with other already-pervasive tracking methods, advertisers may actually find it easier to identify you.


Your browser gives up all kinds of information when you use it, such as the fonts you have installed, your IP address, the device you’re using, etc. By combining these snippets of data, a surprisingly individual profile can be created, then used to track you across sites. Apple’s Safari browser limits much of this data already, but not all. Other browsers may give more away.

People shouldn't have to accept being tracked across the web in order to get the benefits of relevant advertising.

"Publishers and advertisers already use some very clever fingerprinting methods where cookies have been regulated," self-confessed ad-tech entrepreneur Jake Lazarus told Lifewire via email. "As these are only recalculated weekly, FLoC can be used to compound existing fingerprinting techniques to make them more accurate, but also to link what is a pseudo-anonymized user ID to demographic data, something that is quite hard to do otherwise."

By combining FLoC bundles and individual fingerprints, a tracker can quickly home in on an individual. It only has to distinguish your browser from the thousands of others in your FLoC bundle, and not from the hundreds of millions of users on the general web.

Tracking is Not a Right

In a blog post detailing the plan, David Temkin, Google’s director of product management, ads privacy, and trust, quotes a Pew study that found 72% of respondents feel they’re being tracked, and 81% say the risks of tracking are not worth the benefits. And yet, Temkin continues as if the web cannot operate without some kind of user tracking, even if Google doesn’t want to call it tracking.

"People shouldn't have to accept being tracked across the web in order to get the benefits of relevant advertising," says Temkin, "And advertisers don't need to track individual consumers across the web to get the performance benefits of digital advertising."

two woman facing security cameras mounted above door
Matthew Henry / Unsplash

Even if you accept that the web has to be ad-supported, ads can operate just fine without tracking. Podcasting has worked without tracking of any kind. Its ad model uses download numbers. And before the internet, the entire world of ads operated without tracking.

The argument seems to be that advertisers have a right to track us, hence the fuss about Apple blocking trackers in the upcoming iOS 14.5.

Advertising will continue just fine without any tracking whatsoever, just like it has up until the recent days of the internet. Cut them all off.

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