You Tube and copyright infringement

there is no copyright infringement on You Tube's part . . . .

A site like YouTube is actually protected by law (the Digital Millenium Copyright Act, or DMCA) from being sued. The reason is that YouTube does not actually post content. It is simply a service that allows users to post content. Under the DMCA, they have "Safe Harbor" protections as a service provider. You may recall that Viacom sued YouTube, but there is a good chance that they would have lost. YouTube chose to settle for two very good reasons. One, it would have cost them a lot to defend. Two, they would rather the courts not test the DMCA when somebody with the money and clout of Viacom is sitting at the other table. Most of us do not have that kind of money. Of course, there are things they must do in order to maintain that Safe Harbor status. If the site where you find the infringing material is one where the operators of the site post the content then they have no protection under the law.