LONDON (AP) — The British government says that starting next year pornography websites will have to verify that their users are at least 18.

The government says that from April 2018 websites will have to show they are blocking access by minors, possibly by making users supply credit-card details. A regulator will have the power to fine those that fail to comply.

The National Society for the Prevention of Cruelty to Children says the move will protect young people from "deeply damaging" imagery.

But the Open Rights Group says the rule may let websites build up databases of users' personal information and porn habits. Executive director Jim Killick said Monday that the information "could be vulnerable to Ashley Madison-style hacks." In 2015, hackers stole details of millions of users of the infidelity website.