What is Federated Learning of Cohorts (FLoC)? Is it a harmful technology?

For two decades, cookies (perhaps the worst part of the Internet) have been the focal point of the web advertising industry, worth billions of dollars. Fingerprints are difficult to stop. One, if not the most important of the colossi of the online advertising industry is Google.

Google wants to replace cookies with a new suite of technologies for web ads. One of his proposals - Federated Learning of Cohorts (FLoC), is probably the most ambitious, and potentially the most damaging.

FLoC is meant to be a new way to get your browser to create profiles that were tracked by third-party followers.

Here's how:

- Reducing / concentrating your recent browsing activity into a behavioral tag and then sharing it with websites and advertising agencies.

- The technology will avoid the privacy risks of cookies, but may exacerbate the most serious non-privacy issues with behavioral ads, including discrimination.

- A browser with FLoC enabled would collect information about its user's browsing habits, then use this information to assign the user to a "cohort" or group. Each user's browser will share a cohort ID, indicating the group they belong to, with websites and advertisers. According to the proposal, at least several thousand users should belong to each cohort.

In short: the FLoC ID will be like a brief summary of your recent web activity.

FLoC cohorts will be recalculated weekly , each time using data from the previous week's navigation. This will make FLoC cohorts less useful as long-term identifiers, but show how users behave over time.

Google has promised that the vast majority of FLoC cohorts will have thousands of users, so a single cohort ID shouldn't set you apart from a few thousand other people.

Information that can be exposed:

- Specific information about browsing history.
- General information about demographic data or interests.

Google is testing FLoC on Chrome users around the world. Find out if you're one of them here .

According to Google, the study currently affects 0.5% of users in certain regions, including Australia, Brazil, Canada, India, Indonesia, Japan, Mexico, New Zealand, the Philippines and the United States.