Not that it's any more legal or ethical, but there's a large difference in perception between stealing content from large companies (media companies) to rehost on a free platform and stealing from starving artists and claiming it as your own. It is my understanding that YouTube grew largely by the former.
There needs to be CRC/SHA for video. Once that is figured out identifying these sorts of things will be trivial.
I would in fact pay someone to develop this as I think it is something humanity needs. Or I could pivot it into a startup and offer content creators a "safe harbor" to let them know whenever their stuff has been pirated.
Isn't this what YouTube calls content ID? They alert you that your content is up somewhere, then you have the option of monetizing it, or having it taken down.
Not quite trivial: people can crop, skew, vignette, mirror, timestretch and scale video to try to defeat it. YouTube's Content ID seems to be vulnerable to this sort of thing still.
I think that's why many of these systems focus on audio. It's harder to change in a way that beats fingerprinting but doesn't ruin the viewing experience.
