Mastodon seems great for excluding the really unpleasant types who were on Twitter but the danger the other way, of course, is the risk of becoming an echo chamber. Brexit and Trump really shocked me and I would have preferred to have known people thought that way in advance.

What if, say, all the climate change denialists find they like life on one of the generally-blocked instances? Do we all need several accounts? Maybe there's a tech solution, like some clever aggregation to make a digest.