I'd be more interesting to build a tool to detect all the videos in Youtube that fall under fair use but are still being DMCA'd.
The problem is incredibly complex, because Fair Use doesn't have any quantifiable metrics that you can translate into a computer algorithm. The gist of Fair Use is that you have to prove the intent of the uploader trying to rip you off.
As you can imagine, this is a very hard thing to prove and the amount of videos being uploaded every day makes this is even harder to crack.
If you're interested in this problematic, reach out and I will be happy to share more.