A U.K. law requiring that pornography websites verify the age of their users took effect Friday.

The BBC reports that around 6,000 porn sites have said they will start verifying users’ ages to comply with the Online Safety Act, although at least one major site was not requiring age checks as of Friday morning.

The law also requires that online platforms prevent children from being exposed to harmful content, which is why sites like Reddit, Bluesky, X, and Grindr have also begun asking users in the U.K. to verify their age through means including selfies or government-issued IDs.

This is just one of a number of new child protection laws that could normalize online age checks globally, according to Wired. The approach has been criticized by groups such as the Electronic Frontier Foundation as a threat to online privacy and anonymity — indeed, it’s worth noting that in a recent breach of the dating safety app Tea, many of the affected images were selfies and digital IDs uploaded for account verification.

Some internet users may try to get around age checks by using fake IDs, selfies of video game characters, or VPNs.