Did anyone think Mastodon was safe from mobs? What Twitter has already made clear is the scope of the problem of social media moderation in an open-follow model. It's actually a core problem to be solved, VC economics do not incentivize solving it, and solving it in a distributed system is potentially orders of magnitude harder. The bottom line is that it's not easy when 1 out of a 1000 people can make life miserable, and many of these people having nothing better to do in their lives then to just stir the shit all day every day.

Personally I think broad social media will inevitably devolve into a Bladerunner-like cesspool, and all meaningful social activity will move to smaller, closed, or at least heavily-moderated groups.