SAN FRANCISCO - Meta’s landmark settlement with nearly every US state promises curfews and time limits for teens on Instagram and Facebook — but rests on age and parent checks nobody has figured out how to make work.

Meta agreed over the next decade to restrict teenagers’ use of Facebook and Instagram to two hours a day and block all usage from midnight to 6 a.m., absent parental consent.

It agreed to independent testing of age assurance standards.

Meta will pay up to eighteen billion dollars to settle claims regarding child engagement. States alleged social media platforms enticed and retained young users, misleading the…