I don't think we ought to ban anonymity, but I think we should make it a requirement for social networks to display country of origin. Unfortunately that's impossible because of VPNs. Perhaps a system where you're identity is verified by a third party, all documents erased, but leaves you with a permanent token that allows you to authenticate as a citizen of some country.
The upcoming EU digital wallets in theory could do this kind of thing. They're focused on anonymity preserving age verification right now, but exposing any other government-verified attribute anonymously should be equally possible, including residency and/or citizenship if that's your bag.