Memes

Depends on your instance and the community you're posting in.

For example, on lemmy.world a user might get warned or banned for openly celebrating the shooting of Brian Thompson. (I forget exactly where they draw the line, but it's an "advocating violence" thing)

Or here, a user on lemmy.ml might get banned for bigoted statements, even normal things that plenty of people don't even notice are bigoted because it's "common sense" in their own country.

But you've got to be pretty damn intolerable to get banned from more than a few instances. Like, actual Nazism.