ProofToken16: My Proposal for Private Decentralised Age Verification

So there's this whole thing now about how under-16s aren't meant to be allowed on social media, and this is supposed to be enforced through technical means using Zero-Knowledge Proofs, or something. Here is my proposal. Let's disregard the declaration of the independence of cyberspace for a moment and assume that actually we changed our mind and we do want the government to be mandating age verification on the web, and let's say we don't mind the fact that enforcing "no social media for under-16s" actually places the burden on everyone over 16 to prove it. Let's assume the requirements are: websites have a way to test whether the user is over 16 websites can't learn any private information other than whether or not the user is over 16 multiple decentralised issuers can provide proofs-of-age new issuers can be created without websites having to be updated to accept them the website can't tell which issuer you used this whole thing isn't secretly a tool to expand the surveillance state,…