"505 capacity by the software and designated a supernode, or to some other computer with comparable power and capacity to collect temporary indexes of the files available on the computers of users connected to it. The supernode (or indexing computer) searches its own index and may communicate the search request to other supernodes. If the file is found, the supernode discloses its location to the computer requesting it, and the requesting user can download the file directly from the computer located. The copied file is placed in a designated sharing folder on the requesting user’s computer, where it is available for other users to download in turn, along with any other file in that folder. In the Gnutella network made available by Morpheus, the process is mostly the same, except that in some versions of the Gnutella protocol there are no supernodes… . . Although Grokster and StreamCast do not therefore know when particular files are copied, a few searches using their software would show what is available on the networks the software reaches. MGM commissioned a statistician to conduct a systematic search, and his study showed that nearly 90% of the files available for download on the FastTrack system were copyrighted works. 2 Grokster and StreamCast dispute this figure, raising methodological problems and arguing that free copying even of copyrighted works may be authorized by the rightholders. They also argue that potential noninfringing uses of their software are significant in kind, even if infrequent in practice. Some musical performers, for example, have gained new audiences by distributing their copyrighted works for free across peer-to-peer networks, and some distributors of unprotected content have used peer-to-peer 2 By comparison, evidence introduced by the plaintiffs in A&M Records, Inc. v. Napster, Inc., 239 F.3d 1004 (C.A.9 2001), showed that 87% of files available on the Napster file-sharing network were copyrighted, id., at 1013."