We have an AI ban on our art focused Discourse and so far it was received pretty good. This was kinda expected form an art community. For images we had a strict ban from the start. We later extended the rules to all generated content, including text and code (with an exception for if it is just a translation to not punish non English speakers just for not speaking the language). When the ban was extended to code (like plugins for the painting software) there was a bit of a debate but mostly just by a few people. In our case it is also kind of expected to ban AI and take a stance against it after all the damage it has done to the art community as a whole. Once in a while plugin creators complain but we tell them they can do whatever they want just not post it on our forum and that’s mostly okay for them. Sometimes you get the occasional “your software will be let behind if you don’t allow this”, trying to threaten, FOMO, or guilt trip us into reversing the rule, but mostly its quiet.
As for moderating, we mostly rely on our community. We have an extra flag to report AI content. When it comes to checking we don’t want to create a community of mistrust and suspicion so we assume everyone as innocent first and when we can’t really prove that something is AI it normally can stay. We don’t want to make it a witch hunt and accidentally ban a user that is completely innocent just because their artwork looks like AI, when in reality it is the other way around.
Luckily often enough AI users sooner or later accidentally reveal themselves by forgetting to remove the generators watermark, the file name has still something like “gemini generated image” in it, or the style or quality varies drastically.