@hawkeye10,
Best I can tell, the ones I have in mind are far-left wing extremists. The "skinheads" of the left, you might say. Right wing neo-nazis would probably be banned immediately, but the same tactics seemed to be condoned if coming from the other side.
You're right that in one sense it's a serious matter. The rhetoric of all extremists, of any type, seems to share such characteristics as: (1) fanatical certitude (2) hostile intolerance (3) unsubstantiated demonization, and (4) amateurish simplification.
It's basically hate-mongering. But at the same time it's comical, to me, at least.
Same with the conspiracy theory wack-jobs. They're basically harmless and I would never try to argue with them or display my "superior wisdom" by repeatedly mocking them. I just chuckle.