A troll (no matter how low-level) wastes time, ruins people's mood, and destroys trust.

Every actual troll increases the probability that some other innocent newcomer will get accused of trolling wrongly, making a community just that tiny bit more hostile to newcomers, and thus less open to the outside world. Then those newcomers judge the community badly for the community's negative judgment of them. Bad feelings all around, and a community which is now less receptive of new ideas, because they might just be trolling.

So, yeah, trolling does damage. Trolling is bad, bad, bad.

It could be argued that such trolling can cause circumstantial damage or emotional damage, through intermediaries, with an example that takes a couple of weak steps in reasoning.

It could be argued back that this is circumstantial, and therefore not caused knowingly by the troll, and the example taken apart by all those weak points by giving them actual numbers for their probability.

Then it could be counter-argued again that the amount of possible circumstances or possible combinations of circumstances that would bring about some form of damage is such, compared to the circumstances that would not and the probabilistic facts of the trolling, that it ends up being more likely than not that at least one out of the incredibly many possible sets of circumstances will apply for any given instance of trolling.

I need a sanity check for motivated stopping here, but I don't see any good further counter-argument that I could steel-man and would show that this isn't a case of "trolling causes damage in a predictable manner", unless my prior that such damage would not occur in the absence of trolling is completely wrong.

Public notice: I'm now considering this user a probable troll and will act accordingly.

In the future, I may so consider and act, under these sorts of circumstances, without such public notice.

Does any (old-time, trusted) user want to volunteer as the mod who goes back and deletes all the troll comments once a user has been designated a troll?