People in Louisiana who visited Pornhub in recent months were met with a surprising new demand. Before they could stream sexually explicit videos, they had to provide proof that they were at least 18.

That’s because Louisiana lawmakers had passed legislation last year requiring publishers of online material that could be “harmful to minors” to verify that their users were adults.

Louisiana is at the forefront of a sweeping national push to insulate young people from potentially harmful content by requiring certain online services to bar or limit minors on their platforms. As a result, people in many other states may soon find that they, too, need to use credentials like digitized drivers’ licenses to access a host of services, including popular social media apps.

The proposed restrictions, introduced by at least two dozen states over the last year, could alter not only the online experiences of children and adolescents. They could also remake the internet for millions of adults, ushering in a tectonic cultural shift to a stricter, age-gated online world.