In March 2021, Google began testing its new ad-targeting initiative called Federated Learning of Cohorts (FLoC) with a subset of Chrome users. The plan is to implement FLoC as an alternative to cookies—which are being phased out—to track online behavior.
While Google says that the new measure is designed to respect user privacy, others claim that FLoC creates more problems than it’s trying to solve. Entities like the Electronic Frontier Foundation (EFF) argue that it’s still possible for bad actors to link Google’s anonymized cohort IDs with individual people.
FLoC works by monitoring people’s browsing, assigning their aggregated behavior an ID, and then grouping browsers with similar browsing behaviors together. The data from these groups, called cohorts, is then used to show people targeted ads.