I constantly block people on the Internet based on the content they deliver, how they answer, whether they are logical and polite, or leap straight to manipulations, lies and insults.
Some think it's a radical approach, but I don't see it that way. For all its capabilities, the Internet isn't real and neither are the relationships we have with people on numerous sites that form its social aspect. Thus, there's really little logic in giving people second chances, wasting time, attention and effort for them, trying to get through their attitudes and suffering to reach "real" them.
It's like "you have the chance to be polite and reasonable - resign from this chance, and I'm gonna resign from you".