Now I was reading the mailing list a while ago, and I thought of a memorable experience from when I was editing Wikipedia as [[User:Ziggy_Sawdust]].
On the Reference Desk, some of you may recall a character called the Avril Lavigne troll. He used about 10 IPs, an army of redlinked accounts, and asked a bunch of ridiculous questions, mostly pertaining to Avril Lavigne, but the unifying characteristic was that none of them had any place on the Reference Desk, let alone Wikipedia. He did do some vandalism to the Reference Desk header too, but that wasn't a primary part of his actions.
Now what I did is I set up a subpage on my userspace. He and I agreed that he could ask his redonkulous questions there, I (or whoever else wanted to) could answer them, and he would leave the Reference Desk alone.
He did.
Now this isn't going to be representative of all "trolls", of course, but for some of them, yes. What have we learned? That sometimes, if someone wants attention, we should make a small compromise and give them what they want instead of flat-out denying it, which would make them seek it harder.