Randy raises a fascinating question below about the appropriate uses for Peer-to-Peer technologies, and he and Tim Wu have begun an interesting dialogue in the comments. Let me suggest an alternative answer to Tim’s.
Peer-to-Peer technologies have substantial utility in those circumstances where anonymity or decentralization are desirable. So, as Ian Clarke has long argued with respect to Freenet, peer-to-peer can be an effective mechanism for enabling free political speech in those parts of the world that have repressive governments. It is relatively easy for a repressive government to shut down one or a dozen central servers, but virtually impossible for them to shut down all content-hosting peers, unless they’re willing to turn off Internet access altogether. Similarly, with central severs, it is much easier to compile a list of the Internet addresses belonging to content downloaders, but much harder to do this effectively when the distribution channels are peer-to-peer. There is enormous potential for these kinds of technologies to promote freedom and democracy in authoritarian regimes and robust, uninhibited debate in freer societies where legal liability concerns and social norms constrain discourse unduly.
At the same time, anonymity and decentralization have substantial downsides in the speech context. Darknets facilitate child pornography distribution. Peer-to-peer allows privacy-invading MPEG files to spread across the globe in hours, well before any court can intervene with injunctive relief. And anonymity and decentralization on P2P can contribute to the rapid spread of computer viruses, thwarting efforts to control viruses through the imposition of legal liability on content providers and disseminators.
So we have an environment in which P2P creates substantial speech-related benefits and speech-related harms. In these settings, we can resolve this issue in one of two ways: Compare the magnitude of the benefits and harms (This is what the Ginsburg concurrence in Grokster seemed to want to do – More people want to use Grokster to obtain porn than political theory); or give the benefit of the doubt to the “more speech is better” philosophy, and tolerate many less savory uses of P2P for the benefit of the occasional blessed use (This seems closer to Breyer’s view of Sony in Grokster.). The former is how the law usually handles economic policy questions, and the latter, I think, is how it handles many free speech questions. So doesn’t this all boil down to the question of “What is Peer to Peer use: Economic conduct or speech?”