I wonder if a lot of it is bot accounts in the employ of the security services. Not all the users, but enough in key positions to shape the narrative. A safe and harmless way of neutralising disaffected youth. And for those who won't be neutralised, a little encouragement to commit a crime that can be 'stopped' or let happen to justify more funding. Harder to do that in Marxist spaces (I'm sure there are examples), as Marxists argue against adventurism/propaganda of the deed/lone-wolfism and argue for organising the masses.