Trolls are people who target a specific person or group and all they just want to do is piss you off greatly. As well twist a few words into an insult for an example
Me: vampires arent ment to sparkle
Troll: THEY DO NOW!! vampires are now deemed fairy faggots!! and your one to from believing in them!!!
Me: SGRGARHFRJFZ!!!!!! YOUR A FAGGOT!
Troll: thats what she said! LMAO

theres only one way to deal with them. just ignore them and dont get invovled. pretty simple
but some people are stupid and they go off on a flaming war.

:3 hope it helps

Trolls are idiots that get their kicks by pissing other people off.
This comic sums them up pretty well. http://www.viruscomix.com/page483.html
As the previous commenter said, the best way to deal with them is ignore :3