Because otherwise you run into nonsense like this for just-for-fun, non-commercial use of a song. From an e-mail that YouTube just sent:
A copyright owner has claimed it owns some or all of the audio content in your video defiance ohio in australia: (http://www.youtube.com/watch?v=_nJLa8F1VY4). The audio content identified in your video is Highway To Hell by AC/DC. We regret to inform you that your video has been blocked from playback due to a music rights issue.
Larry Lessig, an intellectual who was instrumental in the Creative Commons framework was recently interviewed about copyright enforcement on the Colbert report:
Colbert: You say our copyright laws are turning our kids into criminals, because they’re keeping kids from doing all the remixing they want of pre-existing art and copywritten material, right?
Isn’t that like saying that arson laws are turning our kids into pyromaniacs?? They’re breaking the law! You can’t just throw the law out the window!
Lessig: “Totally failed war.” Is that familiar to you?
Colbert: No. No. You’re saying we need a surge?
Lessig: We tried the surge. For ten years we’ve been waging this war. Artists have not gotten any more money, businesses have not gotten any more profit, and our kids have been turned into criminals.
Link via Boing Boing
Best,
Geoff