Tuesday will see the United States Supreme Court hear on a landmark case in the area of P2P file sharing. The case is set to decide on whether two P2P network operators, Grokster and StreamCast are liable for the copyright infringement committed by their users.

Companies behind P2P software claim that the applications can be used to share legal content, and that they are not liable for what users do with the software. They claim that they are unable to control what happens when the software is used, and as such they are powerless to stop P2P software being used illegally. A court will now decide if this is legally the case or not.

Hollywood and the RIAA say that P2P companies such as Grokster and StreamCast are no different from the old Napster, and have built their business by encouraging users to share illicit content.

Grokster and StreamCast will be facing an uphill battle against 38 entertainment companies and over 27,000 music publishers and artists.