The best lawyer in America in our opinion is David Boeis. For those of you who are old enough to remember the Recount saga of 2000's President Elections and Bush v. Gore would know the name. He is more famous however in the business world for his role on behalf of the US Department of Justice against Microsoft in the Microsoft anti-trust case.
Here is an excerpt from an interview from Wired about the Napster case in which he represented Napster.
The first issue is: Are Napster's users engaged in copyright infringement? If they are not, that's the end of the matter, because nobody alleges that Napster directly infringes any copyright. Napster's only alleged liability is for contributory or vicarious infringement. You cannot have contributory or vicarious infringement without having some underlying infringement. So when Napster's users engage in noncommercial sharing of music - noncommercial copying of music - is that activity copyright infringement?