Page:United States Reports, Volume 545.djvu/974

 Opinion of the Court 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. In these versions, peer computers using the protocol communicate directly with each other. When a user enters a search request into the Morpheus software, it sends the request to computers connected with it, which in turn pass the request along to other connected peers. The search results are communicated to the requesting computer, and the user can download desired files directly from peers’ computers. As this description indicates, Grokster and StreamCast use no servers to intercept the content of the search requests or to mediate the file transfers conducted by users of the software, there being no central point through which the substance of the communications passes in either direction.

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. 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