Well if I think about what a troll is doing here, of all places, my conclusion is this: The philosophy forum probably ranks fairly highly on google searches for philosophy, in general. It has a pretty large and active thread named "Donald Trump". So someone looking up something concerning Donald Trump, and maybe the word "philosophy" might end up here. And since almost everyone here is highly critical of Trump, they'd normally find a fairly undivided message: A bunch criticizing Trump and his decisions, and noting possible negative consequences etc.
Now, with our vampiric friend, what they'd instead find is a lively "debate", where every post critical of Trump is followed by a Trump talking point. If someone is already inclined towards a certain position, they can now pick and choose whatever they like. And if someone is inclined to doubt this story or that, they can find confirmation.
The difference is I don’t need any resource beyond simple reason to teach me what’s true or false. — NOS4A2
Another part of the effect relates to derailing - or controlling the conversation - making claims that lure people into responding and thus increasing the "broadcast strength"of the original message if the responses explicitly correct it and react to it rather than providing their own narrative. Even if everyone who responds to it disagrees with it. The "lure" works by exposing skeptical or hitherto unexposed people to a claim, or a framing context for a claim, in a situation of heated debate; so when you just "skim over it", you see good points from both sides, but one person (like @NOS4A2) is controlling the flow of conversation - what topics get brought up in what way, and what easy refutations there are for them.
It's not infallible, — unenlightened
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