Jimmy the Fail strikes again
The reason Wikipedia has problems with trolls:
1) Anonymous users can edit the site
2) They insist on not tieing usernames to real identities
3) No limit on the number of usernames you can use
If he actually cared, there are two or three simple technological solutions that would remove the vast majority of wiki trolls, but he doesn't care.
Plus, in most cases trolling is not illegal. Where it is illegal, get the police involved, but calling the fuzz because someone keeps calling you a tool on facebook is retarded.