There might be a need to handle the cross-community spammers on an instance or Fediverse wide level though, in particular the ones who post to any porn community with the same title and picture regardless of the picture/title being on topic for that community.

The downside of that is that a lot of OF content is posted to dozens of communities and this fact is the main spam problem with them, not necessarily the content in any particular community on its own.

You can easily look up the owner of the IP address space to get the provider.