I have seen people comment very aggressively to bad users on SO, and even their legitimate programming questions get voted down or even closed.
See for example the comments and down votes on this question - see other questions by this user too.
I appreciate that bad users should be punished, but to have legitimate questions down-voted/closed and aggressive comments posted seems counter to the purpose of SO.
What is the "right" reaction?
How should one respond to the comments that demand that the user accept answers?
Edit: Guess I need to rephrase my question: Is aggressive commenting and down-voting and closing of (perhaps badly phrased but) relevant questions considered acceptable behavior on SO?
Please don't get hung on details discussing the specific bad user I linked to, he is not the only one.