Something tells me there would be agreements between the instance provider and a media hosting provider and as such the media hosting provider would probably have some disclaimers about what they’re willing to host (war porn, regular porn, what have you). The two host providers would have to make sure everything they want to provide and everything they don’t want to host agree. I mean, there’s already lemmynsfw, so free porn hosting is already happening.

I honestly think the whole media hosting aspect of federation is dangerously flawed as long as instance hosts are still paying for storage and bandwidth, and I’m not sure how to fix it. It will cripple small instances with popular media if they host directly, but not hosting directly has a possibly lesser impact on all instance providers, with a higher aggregate impact. Tough choice. I don’t know enough about CDNs to say if that can solve the problem, depending on how media is federated.

This is going to need to be resolved if federation is going to grow to the next level. I hope someone finds an answer that works well enough for everybody, even the porn users and providers.