Idk how many trolls there might be total. I’ve only encountered one who is an absolute sadist. I realize the article you posted said that sadism is a common thread. I still don’t see it as *that* common though. I think the average troll has an anti-social personality disorder, enjoys disruption and craves attention. I don’t personally believe the majority of trolls are sadists.
If you think someone is trolling FR, report it to the mods, you may just get results.
If nothing else, the proprietor’s should realize it’s in their best interests to keep the forum civil and a decent place for discussion, and not drive people away.
(not sarcastic, actually, kind of Pollyanna-ish, but I’d hope that TPTB are smart enough to figure that out.)