First, let's skip over the whole idiotic concept of twitter as a serious medium of communication (quick, here's 140 chars, tell me everything you know), and go to places that you can actually write coherent sentences - that'd be anywhere from email, to usenet, to websites that allow long comments (or your own website).
Back in the day, we used to get trolls on a usenet group I was a regular in. Some where drive-by shooting, never seen again; frequently, we made sarcastic comments about their post. Then there were the longer posts, from someone who might even come back.
Y'know, I understand that about 1,000 years ago and more, if a bard, or someone, made a satire of you, you might as well kill yourself, because no one would ever forget it (admitedly, they didn't travel a lot back then, and the supply of humor was a lot smaller).
Our answer was to MST3k that person. Doing so, of course, requires intellegence, a good familiarity with language, and frequently, some basic logic. I don't think *anyone* everr came back after being misted....
It's a much more elegant solution, and more enjoyable to everyone else, than to simply JUMP DOWN THE ASSHOLE'S THROUGHT WITH COMBAT BOOTS ON.
mark "come on, meet me at x, and show me that you meant that crap"*
* Now, my sword, my walking stick, or just 911?