Wow, that is kind of a bizarre ruling. Unpacking it from the current context of finding file sharers, on what grounds should a court get to decide that a production loses all copyright protection solely because of its content? It's not just the sex acts but the performers, I presume, that give value to a porn video (and of course, production value and story writing).

I suspect that some athletic broadcasts enjoy copyright protection by the league and yet it'd be strange to deny their copyright just because it's a bunch of guys kicking a ball around