Lemmy.ml has fully went communist even their application needs you to copy paste a part from a communits book and that’s ok by me every politkcal group has their own instance and has the right to do as they wish . But they should really change their about from foss and privacy advocated to communist leaning .
They can ban them from either the instance (no one on .ml will see posts from that user) or from this community (no one viewing this community on .ml can see content from this user). Either way, it only affects the .ml instance since they’re not mods for asklemmy@lemmy.world.