What landed me here: on chem SE we've had an upset User who's complained about broken images in posts and uneven/unfair moderation:
chemistry.meta.stackexchange.com/questions/5458/…. Handling of this has not been superior, and the complaints might have some basis (who does not chafe occasionally on SE). But the person is persistently aggressive and convoluted in their arguments and their behavior close to trolling or baiting.