It's not often a decision about the legality of downloading a free digital track belonging to Metallica affects publishing at-large, but when the U.S. Circuit Court of Appeals ruled against Napster, the controversial online file sharing provider, it sparked questions about digital publishing's overall shelf life. This week's 58-page ruling requires that Napster stop trading copyrighted content online—in the U.S., at least. But whether content is downloaded for free or for a fee, the Napster debate has fueled both kudos and criticism of a system that challenges traditional content rights laws. Thanks to the music market's equivalent of Robin Hood, publishers are learning critical lessons about the pros and cons of file sharing.