EFF 2021 Analysis
Title: Google’s FLoC Is a Terrible Idea
Authors: Bennet Cyphers (EFF)
Abstract/Summary: We wrote about FLoC and the other initial batch of proposals when they were first introduced, calling FLoC “the opposite of privacy-preserving technology.” We hoped that the standards process would shed light on FLoC’s fundamental flaws, causing Google to reconsider pushing it forward. Indeed, several issues on the official Github page raise the exact same concerns that we highlight here. However, Google has continued developing the system, leaving the fundamentals nearly unchanged. It has started pitching FLoC to advertisers, boasting that FLoC is a “95% effective” replacement for cookie-based targeting. And starting with Chrome 89, released on March 2, it’s deploying the technology for a trial run. A small portion of Chrome users—still likely millions of people—will be (or have been) assigned to test the new technology.
Other: EFF also released this website for users to check if they were part of the FLoC origin trial.