what is the principle of law in this case and the decision?

Selling Entertainment on the WebNapster Inc. provided a free service for visitors to its website that allowed users to share music digitally. Napster did not receive permission from the owners of the music. Several large recording studios that owned much of the music that was being shared filed a lawsuit against Napster, requesting that a federal court order Napster to cease its free online file-sharing service. Will the recording studios be successful in convincing the court to order Napster to cease these operations? [A&M Records Inc. v. Napster, 239 F.3d 1004 (California)]