~~1st kind. REPORTER TROLLS. Hated by virtually everyone. And I bet deep down they hate themselves, because they are so pathetic that they have nothing better to do than report (usually innocent) Qs and As on Yahoo Answers. If you suspect someone of being a troll: BLOCK!! Trolls rarely have avatar pictures or screen names, but sometimes they do so beware.
~~2nd kind. Trolls like Phil J. Yes hes the most famous one. Ooh I bet his mummy's proud that ickle Phil has become famous on the Internet. But not for writing excellent poetry, or cracking hilarious jokes. Oh no. Phil J likes to "entertain" us with stories of how his girlfriend poops on him while he touches himself. He'll end his disgusting little story with "..it was a lot more erotic than I expected".