Tankies, Nazis, Trumpists, Transphobes & other Bigots, Anti-vaxxers, folks who say "scratch a liberal..." or "genocide joe", and other assorted pillocks. Don't need these know-nothing fools in my feed.
Asses in replies, mostly. But also weirdly dramatic people who do stuff like argue with trolls ad nauseam, saying needlessly critical stuff like "are you surprised?", along with anything demonstrating that no further (or any) interaction is profitable or needed.