anonymity and privacy seem to come at odds with a social platform’s ability to moderate content and control spam.
If users have sufficient privacy and anonymity, then they can simply use another identity to come back, or use multiple identities.
Are there ways around this? It seems that any method of ensuring that a banned user is kept off the platform would necessitate the platform knowing information about the user and their identity
Those are reasonable options - though I’m pessimistic enough to believe that trolls will get better than every automated system, so we’d probably want some manual options. I wouldn’t say it’s not possible - just would require quite a bit of work, and would likely be an ongoing battle to improve your auto-moderator.
It feels like I’m moving the goalposts, so apologies, but your response got me thinking further. The other big advantages I can think of for central censorship is that it can actually prevent hosting of content - which has two benefits:
first, just to clarify, I am not saying all moderation should be automatic. That is what I said in my first point, but in my second point, moderation is still manual and delegated to another person. The only difference is that you can very easily opt-out of it without losing anything else, or you can override it.
so, instead of moderation being something tighly coupled with a community or space where people post, it is instead something separate. You can “subscribe” to a moderation policy managed by someone or a group of people, and anything they ban (automatically or manually) applies to you without extra effort. The benefit to this is that if you ever regret this “subscription”, you dont lose out on the entire community. You can simply just change the moderation policy.
To answer your other points: