Here are two situations:
There are several adult web-sites that are dedicated to collecting nude and sex scenes done by actors and actresses in mainstream movies and making these clips available for a fee.
Obviously this is not legal, but why does no one do anything about it? Is it just not worth it to movie companies compared to the distribution of full pirated movies?
There are several adult web-sites that specialize in Japanese porn. Specifically, what they do is obtain pirated Japanese porn and then make them available on their own web-site for a price. So basically they are making money off of work done by Japanese companies in Japan.
Again, this seems illegal to me, and I think the reason that these sites get away with it is because no one in Japan cares. That's great, but does that also mean nobody in America cares?