On March 30, Bennett Cyphers wrote:
Today, Google launched an “origin trial” of Federated Learning of Cohorts (aka FLoC), its experimental new technology for targeting ads. A switch has silently been flipped in millions of instances of Google Chrome: those browsers will begin sorting their users into groups based on behavior, then sharing group labels with third-party trackers and advertisers around the web. A random set of users have been selected for the trial, and they can currently only opt out by disabling third-party cookies.
Although Google announced this was coming, the company has been sparse with details about the trial until now. We’ve pored over blog posts, mailing lists, draft web standards, and Chromium’s source code to figure out exactly what’s going on.
Read more on EFF.