This would require identification of rogue "protected" users, to kick them out, thus ruling out using any sort of blind verification and ruining online privacy

This would require identification of rogue "protected" users, to kick them out, thus ruling out using any sort of blind verification and ruining online privacy for those using it. And naturally, it's marginally more convenient while being extremely detrimental to privacy, thus it'll be popular, thus services will eventually block non-"protected" users, thus ruining the internet even more.