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.
lemmy.ml is a trap run by literal communists (who also happen to be the main developers of the lemmy software) it's basically like the Lion King scene "but what's that shadowy place?" "oh that's lemmy.ml, we don't go there"
But the nice thing about federation is that even thought it's run by the developers, we don't have to participate there and they evidently don't want us "sheep" to participate there either so we can have a mutually beneficial relationship of not having anything to do with one another.