I had a throwaway Reddit account get banned from a local subreddit because I used an em-dash when asking: "Do you have an alternative to Facebook — e.g. a mailing list?" The mods' full response when I asked about it was: "AI".

And it really couldn't have been anything other than the em-dash because I've been deleting the account's comments when they were about a week old so there were no previous comments to draw any conclusions from.

I don't care though, I've been using em-dashes since the late '90s making me partly responsible (along with all the other em-dashers) for LLMs being so fond of them, so I'm not going to stop just because of them.