The Court also ruled unanimously that Internet file-sharing services can be held responsible if they intend for their customers to use their services primarily to illegally swap copyrighted material, even if they have no direct control over what their users are doing. Writing for the majority, Justice David Souter said, "We hold that one who distributes a device with the object of promoting its use to infringe copyright, as shown by the clear expression or other affirmative steps taken to foster infringement, is liable for the resulting acts of infringement by third parties."
The ruling sends the case back to the lower court, which had previously ruled in favor of Grokster and StreamCast Networks on the grounds that the companies couldn't be sued. The lower courts based their decision on a 1984 Supreme Court ruling that Sony could not be sued because consumers used their VCRs to make illegal copies of movies. The lower courts reasoned that file sharing software does have a number of legitimate uses and also lacked a central directory pointing users towards copyrighted material. The victory for the entertainment companies gives them an alternative to going after individual users, which is time consuming and has proven unpopular with the public at large.
