I think this is interesting and it can apply to forums too.
I like this one:
I like this one:
Heartless Doll - 10 Trolls Every Blogger Will EncounterThe political dissenter/martyr troll
If your blog is interesting, chances are it's because you take a stand on things. You have political views you feel passionate about. You build a community of people who are interested in these things and who interact thoughtfully and productively about said things. Heck, some people even manage to disagree civilly. Until political dissenter/martyr troll comes around, starting fights with everyone in a comment thread, spewing its passionate anti-whatever-you're-into views all over the productive discussion. This troll will likely get mouthy about how pathetic a blogger is for not entertaining dissenting opinions, all the while only being interested in hearing itself talk (or type, as it were). Political dissenter/martyr troll, what good do you think you are doing? Whose mind do you think you are changing? Troll, you are an asshole.