@msolga,
What all of those trolls have in common in an obsession with one, or at most a few, subjects. In the case of the first person referred to, he is himself the subject about which he obsesses, and hence all the threads he starts about himself.
But those who want to make everything, no matter how unrelated it may be, about their hobby horse, their obsession, are actually more pernicious, because they ruin other people's threads. It's only the people here who are troupers, old hands, who can ignore them and get the discussion on track. An example i can think of, which probably can be safely used because it has been so long since he posted here, would be Zippo. Zippo only ever wanted to discuss the unmitigated evil of the United States, or that the Jews are the ultimate source of all evil. He mostly started his own whacked out threads, but if he did show up in any other thread, it was with the intention of turning the thread into a discussion of how all evil emenates from the United States, or from the Jews.
He's actually not that good of an example, though, because he so rarely derailed other peoples' threads, and was so easily ignored when he did. To construct an exemplary troll without naming anyone now active, the example would be someone who stomps into a thread shouting: "How can you whine about the whales when millions of unborn babies are murdered every year ? ! ? ! ?" and then stomps off to another thread to shout: "How can you chatter on about drunk driving when millions of unborn babies are murdered every year ? ! ? ! ?" and then hurrying off to a thread about political candidates to ask how people can waste their time on such a discussion when millions of unborn babies are murdered every year.
I'd have to say that those obsessive idiots are the worst, because they drag their obsessive-compulsive disorder into other discussions and **** all over the thread.