The screenshot shows the recommendations from https://join-lemmy.org/
[https://join-lemmy.org/]. Still being federated with exploding-heads does not
mean the instance supports them. But it means that shit-heads are allowed to
take part in the discussions on their communities. They do intoxicate the
...
See longer post (not by me) there, if all is true then they should fall under both the spam and mass lemm.ee rule breaking defederation rules, both bigotry and abusive language, though not always in combination.
Also the covenant thing Mastodon has would probably be a good idea.
Lemmy is a confederation of (ideally) self-moderating instances, individual instances can't be expected to take up moderation load that should be covered by other instances -- like the home instance of notorious brigaders like /r/the_donald folk.
What about the moderators of the forums themselves? I would think that is the first line of defense. Instance moderators then step in if necessary, but that will only affect what happens at that instance?