Anything that involves non-consenting people even seeing stuff. I'm even iffy about tasks that are like "get permission from X amount of people to do Y" on a kinky forum or chat, because like, why am I now involved in your play? I didn't ask for that, I just came here to vibe.
I'll fantasize about public humiliation, talk about it, meme about it, but I'll never actually do it. Even beyond the fact that it's my social life at risk, that's someone else's boundary I'd be violating, and that's not right.