Google’s FLoC Is a Terrible Idea
By Bennett Cyphers, March 3, 2021
The third-party cookie is dying, and Google is trying to create its replacement.
No one should mourn the death of the cookie as we know it. For more than two decades, the third-party cookie has been the lynchpin in a shadowy, seedy, multi-billion dollar advertising-surveillance industry on the Web; phasing out tracking cookies and other persistent third-party identifiers is long overdue. However, as the foundations shift beneath the advertising industry, its biggest players are determined to land on their feet.
Google is leading the charge to replace third-party cookies with a new suite of technologies to target ads on the Web. And some of its proposals show that it hasn’t learned the right lessons from the ongoing backlash to the surveillance business model. This post will focus on one of those proposals, Federated Learning of Cohorts (FLoC), which is perhaps the most ambitious—and potentially the most harmful.
FLoC is meant to be a new way to make your browser do the profiling that third-party trackers used to do themselves: in this case, boiling down your recent browsing activity into a behavioral label, and then sharing it with websites and advertisers. The technology will avoid the privacy risks of third-party cookies, but it will create new ones in the process. It may also exacerbate many of the worst non-privacy problems with behavioral ads, including discrimination and predatory targeting.
Google’s pitch to privacy advocates is that a world with FLoC (and other elements of the “privacy sandbox”) will be better than the world we have today, where data brokers and ad-tech giants track and profile with impunity. But that framing is based on a false premise that we have to choose between “old tracking” and “new tracking.” It’s not either-or. Instead of re-inventing the tracking wheel, we should imagine a better world without the myriad problems of targeted ads.
We stand at a fork in the road. Behind us is the era of the third-party cookie, perhaps the Web’s biggest mistake. Ahead of us are two possible futures.
Update, April 9, 2021 : We’ve launched ▻https://amifloced.org “Am I FLoCed”, a new site that will tell you whether your Chrome browser has been turned into a guinea pig for Federated Learning of Cohorts or FLoC, Google’s latest targeted advertising experiment.