Looks like I'm late to this particular ZOT!
My son owns a board based upon computer graphics. It also has other categories such as miscellaneous and debate. We've had a few repeat trolls come our way over there.
Due to the nature of the board there are quite a few college students who participate. On one returnee we finally had to contact his ISP and the college he was attending. (he was posting really nasty porn and since we also have younger teens, we had to take action)
We had to provide proof to the ISP and to the college but he ended up being expelled from school as well as having his home internet connection cancelled.
It can take time but there can be consequences if trolls get to be too much of a pain.
Yeah, I used to post to a forum prior to finding FR.
They got repeatedly hit by atroll named 'Valentine's kiss'.
Later the troll shortened it to "Val."
Eventually we had enough info to take it to the troll's ISP.
We found out then that it was a 14 year old kid posting the stuff.
Made me wonder greatly about it at the time.
But we had to have 'sufficient proof' first.
*snort*