Free Riding on Gnutella is
Free Riding on Gnutella is an interesting report published by the Xerox Parc group. The study found that at least 90% of Gnutella users don't share any files. The researchers also point out flaws in many peer-to-peer file-sharing programs that allow "free riding" as opposed to sharing. However, they don't suggest solutions.
I guess peer-to-peer file-sharing is not a panacea for restoring privacy and toppling greedy corporations - human self interest screwed it up.