>How exactly do they think that parents can ban it?

Like this:

"You're allowed to walk to your friend's house, but don't suddenly sprint out into the street."

Or,

"You're allowed to talk to the librarian, but not the guy who stands around outside with a paper bag in his hands."

Or maybe,

"You're allowed to put things in the microwave, but not metal utensils."

You regulate it - easy and simple. Simply say that it is illegal to provide a social companion to people below the age Og 18

And, y'know, actually enforce the regulation.

I don't think it is wise to get too caught up in enforcement.

- we don't want a society based on control.

Add enforcement proportionate to the risk it posses.

> - we don't want a society based on control.

Bit late, or not, depending on how you look at it.