I used to see this on Reddit, I'm disappointed this behaviour is also on Lemmy.
Users collecting mod status on multiple communities, and then using that power to mass-ban a single user from a bunch of communities.
Modlog show how incredibly trigger happy some mods can be. Minor transgressions, deserving to have their comment removed at least, but then banned from unrelated communities as a consequence. This will only get worse as users become supermods.
Edit: It seems this is how an instance ban is reported, by banning from any communities the user has participated in. Then perhaps it isn't all as bad as it seems.
It's lemmy.ml...
Their mods don't do much, it was likely an admin banning them from everywhere.
It's incredibly common with .ml, and why people are better off blocking the whole instance
A lot of the small ones are like that. And a lot even use a bot to ban if someone isn't subscribed. So it's possible all you did was down ote a brain rot meme and now you're banned from all those places.
I'm not banned (yet), it was something I saw in the modlog whilst checking something else.
I didn't realise it was so common. Why are people so awful to one another :(