There is a big difference between flashing a card at point-of-sale and having to register for a permanent record with the state.

When the database leaks — and it will - we know what it will look like: the AshleyMadison leaks. People died.

There are plenty of technical mechanisms that are available to parents and schools (etc) to block access to this material. None of them need involve the state.

In the end, we must treat this like any other substance that children aren’t ready for. Whether we are talking about taking cannabis, alcohol, pornography, or Tide pods, the most effective protection is parents and educators who care and teach children about potentially harmful behaviors.