Depends entirely on the situation.
I don't mind a good critic now and again, so that doesn't bother me any. Always great to hear someone's impressions.
When it comes to people who aggressively just trying to annoy me, then it depends on the context. If it's something impersonal like a debate (or even a discussion thread I guess) then I don't think anything of it. If it's someone that really just wants to provoke me then I'll either remove myself from the situation, or get nasty about it.
I love a good discussion, but I absolutely do not go in for that whole getting mad and just arguing shit back and forth. Anything I have to say in a heated argument is my final word on the matter, I don't believe in yacking on and on and just getting worked up. I'll admit that when I was younger I used to get involved physically a lot of the time if someone really wanted to 'start shit'. I mean, I gave them the option to leave it be right?
The passive aggressive thing is something that I haven't done. I don't stew about things or keep contact with people that I would feel strongly enough against to hold a grudge.
Jam it back in, in the dark.