> If you want to crack down on code sharing, you'd have to start surveilling who is signing up to what.

Not at all. If you want to find who shares codes at scale, you just track that person. If someone sells hundreds of thousands of codes online, you can just buy one from them and you have proven that they do it.

Again, if age verification is honestly about helping the kids, I don't think it has to be 100% efficient.

> If you want to crack down on code sharing, you'd have to start surveilling who is signing up to what.

Why? One code for one user account per site. If you're paranoid about privacy rotate codes and accounts weekly. As long as you can purchase the codes with cash in IRL stores the privacy impact is minimal.

So this solution is fine for proving your immigration status, getting employment or renting a house, but it's not good enough for browsing porn(to be a tiny bit flippant)?

>>If you want to crack down on code sharing

Right now, all the kid has to do is grab their parents passport while they are not home or asleep, scan it on their phone and they are in. It takes 30 seconds.

With the codes they would either need to convince their parents to generate a code for them, or find someone online who will - which of these solutions seems less prone to abuse to you?

Again, let's not let perfect be the enemy of the good.