> 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.