I agree totally it is a privacy minefield but proofs of ID are already required by many institutions that have far less resources than tech giants. In Poland for example (where I'm from), the National ID is required in all sorts of situations, both online and otherwise.

Also, I never meant to suggest proof of ID would be mandatory to use the service! It would be an additional status you can get optionally, if you want to get extra credibility. If you desire anonymity instead, that should absolutely be your right.

At the moment, you can get a checkmark on your twitter but how you do it is a bit unclear. Technically you have to be somewhat noteworthy, but the bar seems to be really low. If this was an entirely user-initiated process, over time people would associate that status with higher credibility.