The practice of downloading music off the Internet first gained nationwide popularity in 1999, with a service called Napster that enabled users to copy digital music files from thousands of other users connected to the Napster network. Napster was forced to shut its network down in 2001, but dozens of other file-sharing networks have taken its place, and now users are swapping movies and software as well as music files. Users of these services call it sharing; the entertainment industry calls it theft of intellectual property. This volume examines the arguments of both sides.