How do you deal with flag spammers?

I think you may be underestimating the role that the guidelines can have in shaping this behavior, though.

Four years ago, in response to the OP here, @riking offered up a possible warning message regarding flag-gaming:

…But the guidelines actually say the exact opposite of that, and at least heavily imply that flag-gaming may be an effective tool:

(Which basically is exactly how Facebook works — except for the “or by moderator intervention” part, since their first-line seems completely automated at this point — so if mods are going to claim that Discourse doesn’t work like that, it’d be a really good idea to change the guidelines to reflect that claim.)

In addition, @anon36555649 suggested possibly putting the flagger together with their flagee(s) to discuss the issues behind their flagging abuse. I don’t really agree with that suggestion at all as I think it’s a recipe to heighten tensions, not reduce them, but if someone were to go that route it would basically be in direct opposition to the guidelines, which advise users:

Take the really murky, hand-wavey definition of “bad behavior” — a painfully vague term, employed in a situation that calls for being extremely specific and clear — and combine it with a few users who are all too willing to misunderstand, particularly when they think it’ll be to their advantage, and it’s easy to see how these problems can come up.