Here's a good place to start to read some really fascinating stuff about trolls and how they operate:

http://www.google.com/search?q=trolls+and+trolling

Frankly, it has been years since I read such stuff.

For me, the obvious question is: why *wouldn't* trolls, in the strict or looser senses, attack Wikipedia? And it seems to me the answer is equally obvious: there's no reason they wouldn't, and they already have.

Larry