Lemmy has no resistance whatsoever to such content except that while those instances can exist, other instances can defederate from them. Defederation by the larger lemmy instances puts up an effective wall so they’ll be more difficult to discover from within a smaller instance.

Thus, any instance can effectively “ban” any other instance that is okay to host whatever content they wish, while any other instance can continue to remain connectable. This makes it easier to get away from disgusting shit since you don’t need a team of site admins who pick and choose what’s advertiser friendly or not for you, but instead people who legitimately want the best for their communities.

Not sure about the entirety of available options but one thing I think instances are able to do is block other instances… so I guess if an instance became flooded with illegal material, another instance could block it - though I’m not yet sure what that means exactly in this context.

A instance that allows actual child porn would be blocked off completely and probably reported to the authoritys all around the world.