Mozilla Says Google’s New Ad Tech—FLoC—Doesn’t Protect User Privacy

Google’s upcoming plans to replace third-party cookies with a less invasive ad targeted mechanism have a number of issues that could defeat its privacy objectives and allow for significant linkability of user behavior, possibly even identifying individual users.
“FLoC is premised on a compelling idea: enable ad targeting without exposing users to risk,” said Eric Rescorla, author of TLS standard