Hands up everyone who likes AC DC? No? The Who? No? How about a more current band like Green Day? Yes? Whatever your taste, you can generally find a video of your favorite recording star posted on YouTube. I picked those three bands because I happen to like them and I easily found original videos of them performing songs of my choice. The problem is that those videos, as poor quality as they are, breach copyright laws unless deals have been struck with the copyright owners.
The defence used by sites like YouTube and MySpace, which also carries copyright music and videos posted by users, is that they comply with the Digital Millenium Copyright Act and they take down material that infringes copyright as soon as they are notified by the copyright holder. In the case of MySpace, the News Corporation owned site has gone a step further and implemented a proactive system to identify copyrighted material before it's posted.
For recording company Universal, however, the actions of MySpace appear to be too little too late because it has come charging in like a wounded bull and lodged an aggressive law suit. Why it hasn't done the same with YouTube is not clear. Perhaps the YouTube suit is already being formulated; perhaps a deal has been struck with YouTube; or perhaps MySpace is being used for a precedent setting test case so that YouTube can be more easily targeted later.