IDs can be faked, or bought. “The process of age verification is complicated,” he says, and people in charge of these systems need to give them more thought.

But it’s emblematic of a much larger trend: Around the world, and across the United States, age- and identity-verification laws are passing into law.

Some age verification platforms promise to erase your data after a certain period of time, like the seven days that Persona says it will keep the information used to verify your age on Reddit. But ...