One issue that came to mind when I tried to re-write this comment to post it on lemmy_support: a post can be made to communities with completely different rules resulting in commenters following the rules of the community they are in, but not the other community the post was sent to. This seems like a pretty big issue for moderation.

[–] Fissionami@lemmy.ml 1 points 1 year ago (1 children)

That is why defederation and blocking communities happen! If both communities are on far extreme side of the scale then there's no good ground to be made for interaction.

[–] conorab@lemmy.conorab.com 2 points 1 year ago

Only idea I had in mind would be to have the post go to a "home" community and all other communities pull the comments from that one and submit their own comments to that one. If the "home" community has rules that the others roughly follow that might help filter the extreme ends out so you don't just get constant de-federation.

Content allowed on instances:

Instance 1: Content A, B
Instance 2: Content B only
Instance 3: Content B, C

By making instance 2 the home for the post, which by it's own rules only allows content that both instance 1 and 3 allow themselves, you filter out the content which 1 and 3 would hate. Of course, this puts the moderation burden on instance 2. You could still allow instances 1 and 3 to have their own comments which instance 2 doesn't allow, but only they will see those comments.

IDK, I feel I'm starting to see why Lemmy works the way it does. I'll post in !lemmy_support@lemmy.ml if I get a better idea. :)