You can make active queries, with the user's involvement. The verifier can potentially have a prompt with e.g. "The site you were just on would like to know that you are over 21. Would you like to share that with them?"
We do need to get people onto ipv6 so CGNAT can die. Restricted services could potentially disallow signups or require more knowledge (e.g. full ID) if coming from shared IPs as a risk mitigation strategy, depending on how liable we want to hold them to properly validate age. If you've already signed up for facebook at home, obviously you don't need to validate your age again at the cafe.
Fake IDs exist in the real world. The system doesn't have to be perfect, and we can say that there's some standard of reasonable verification that they should do for these sorts of cases.
Personally I'm more in favor of an approach where sites label their content in a way where parents can configure filters (ideally using labels that are descriptive enough that we don't get into fights over what's "adult", and instead leave that decision to individual families), but if we're going to go an ID-based route, there are at least more private ways we could do it, and I think technologists should be discussing that, and perhaps someone at one of these big companies can propose it.
We do need to get people onto ipv6 so CGNAT can die. Restricted services could potentially disallow signups or require more knowledge (e.g. full ID) if coming from shared IPs as a risk mitigation strategy, depending on how liable we want to hold them to properly validate age. If you've already signed up for facebook at home, obviously you don't need to validate your age again at the cafe.
Fake IDs exist in the real world. The system doesn't have to be perfect, and we can say that there's some standard of reasonable verification that they should do for these sorts of cases.
Personally I'm more in favor of an approach where sites label their content in a way where parents can configure filters (ideally using labels that are descriptive enough that we don't get into fights over what's "adult", and instead leave that decision to individual families), but if we're going to go an ID-based route, there are at least more private ways we could do it, and I think technologists should be discussing that, and perhaps someone at one of these big companies can propose it.