Violation of rights to privacy — age verification ties an identity to the request, so if you’re surfing porn or browsing controversial threads, you could be flagged by law enforcement or the other third parties that the state might be sharing data with, such as insurance companies that might infer the wrong things about you. You could be blackmailed, too.

And then there’s also the leakage of those data points to rival nation states, in case of a security breach.

Plenty of bad nth order effects if you just think about it