Good luck in court with that one. "Nostr services only distribute the child sexual assault material, technically the original copy is stored on another service".

It's not really hard to understand. Anything you see on a social media platform is a liability for that platform. If as a platform they shrug and say "not my problem, we don't moderate content" then they're gonna get crucified in court. 

 I am not a lawyer and I don't run a public relay. I also block anything I don't like client side. So, I don't personally have to bother with any of that. Feel free to comment on the liability of any service provider in regards to the facilitation and/or the distribution of illegal material if you are an expert. This would be useful for any public relay operators that read your messages. 

 Understood but I think you'll still be affected as it's an existential problem, the same problem that destroys all of the zero-censorship platforms in the end. The platform devolves into only the worst elements.

The problem is with the absolutist idea of allowing anything and everything. Most normal people don't want that so it's impossible to gain broad appeal without some level of censorship.