If a site creates some opaque token representing the request, and the token is signed by the ID service with no other information disclosure that "The user that presented this is of the appropriate age" that would seem like a reasonable compromise.
Token could be signed out-of-band to obscure the interaction between the parties.
"To enforce it, platforms must age-check their users. In practice that means anyone opening a new account will likely have to prove they're over 16 by uploading an ID or passing a facial age scan."
> likely
It could, of course, use a double-anonymous system like the French one.
Probably not, but I'd rather that they didn't state their guess as fact in the title.
I have absolutely zero knowledge about the area, but doesn't Polymarket just set up bets between users?
If you're a regular bookmaker, who is on the hook for any losses, then yes you would ban successful users. But in this case you just skim off a fee for each "trade" so there's no incentive to ban anyone.
And how does one verify that the public key received belongs to the intended party, rather than a mitm?
If the answer is blind trust in a third party that runs the messaging service then I suspect that you can guess what the people asking those questions are really asking.
I suspect that the number of kids using not using an app on a device that is aware of its locality is a rounding error.
Tesco* phones on some network's family plan must be 95th percentile.
(* other high street retailers are available)