Or ask user's to cryptographically prove they have passed a KYC check from a reputable KYC vendor (e.g. a bank, Clear, etc). Proving they have been KYC'd but not demanding or collecting any of the KYC data is the best approach. It would be a loss leader for Twitter like it is for Venmo and Ca$h App and PayPal. The difference is that Twitter doesn't have a regulatory requirement to collect that information, they just need to know it exists, hasn't been revoked, and can be discovered by law enforcement under judicial review.