I agree, artists will try to do that. Integrating something like "keybase.io" might allow users to make that choice more easily. Again, if you don't make it easy, and part of the default client... people just won't care enough to do it. I have seen no evidence in my life that people will go out of their way to ensure the right people get paid for internet content. Does anyone look at a porn video and think: gee I hope that girl is getting paid for this viewership, rather than some middleman who stole the content. Let me check her SAFEtwitter / etc feed to be sure.
You need it to be built into the system: This content appears to be a replica of a signed original, would you like to view the original content and reward the original producer? Make it easy, and 99% of the people will do the right thing.
Not only that... but copyright holders will recognize that the best way to get paid... is to upload content. This content appears to be a copyright violation, but there is no original available to view, do you still want to download it? Most users will just skip that warning.
Going further, if you allow producers to set prices... well then. Now it gets interesting: This content appears to be a replica of a signed original, would you like to view the original content, for a fee of $0.20 USD?
A fee market like this... for content, and built in to the system would change everything. Because now all content, of any kind, is instantly monetizable via MAID, and producers can set reasonable prices for content and users can choose, themselves, to risk violating laws while being informed of reasonable alternatives.