The copyright claims can be ridiculous. I've seen videos get hit with copyright claims for playing Bach's Inventions on piano. Very frustrating. IMO, putting a copyright claim on 300 year old music like Pachelbel and Bach is the act of a parasite. And the video media companies apparently just rubber-stamp every claim that comes in with no scrutiny at all.

I really hope that "creative commons" licensing eventually does the same thing for music and literature that GNU did for software. There's got to be a business model that doesn't rely upon using the courts to harass other musicians and artists.