Most peer-to-peer systems create overlay networks on the fly whenever they need to overcome congestion or routing problems on the underlying Internet. Overlay networks are also a great place for academics to experiment with new routing algorithms-algorithms too new and untested to let them loose on the Internet infrastructure.

Peer-to-peer is pretty powerful stuff. What we've seen so far-the copyright infringement systems-is really just the beginning. Peer-to-peer could overcome many of the fundamental problems that are facing the Internet today-problems of centralized control, vulnerable servers, and the difficulty that most organizations have scaling. On the other hand, peer-to-peer could also make the Internet's security problems worse, by allowing hackers to create large-scale attack networks. Peer-to-peer could be a boon for the artists and the recording industry, giving them a way of publicizing and distributing their intellectual property for far less than they do now. Yet better peer-to-peer systems could further hurt the recording companies-and not just through copyright violations.

Already, today's peer-to-peer networks do a better job distributing music than the labels do; next-generation networks could implement systems for promotion and even collaborative filtering to make it more efficient for users to find the music that they want to hear. Peer-to-peer systems could even act as a kind of Internet radio system, eliminating the need for radio play and the accompanying payola. This was fundamentally Napster's plan, as the record labels learned during the process of discovery during their lawsuit. The real threat that peer-to-peer poses to the record labels is that it could make them obsolete.

At the end of the day, peer-to-peer technology is about increasing the reliability and the redundancy of Internet-based systems. That's why the recording industry is afraid of it-because peer-to-peer can be used to create networks that the industry can't shut down. But peer-to-peer can also be used to create networks that earthquakes, wars, and terrorists can't shut down. Ultimately, I think that we're better off trying to strengthen the Internet rather than trying to make it weaker.