Diomidis Spinellis writes "Two USC researchers published a paper in the prestigious IEEE Transactions on Computers that describes a technique for p2p content poisoning targeted exclusively at detected copyright violators. Using identity-based signatures and time-stamped tokens they report a 99.9 percent prevention rate in Gnutella, KaZaA, and Freenet and a 85-98 percent prevention rate on eMule, eDonkey, and Morpheus. Poison-resilient networks based on the BitTorrent protocol are not affected. Also the system can't protect small files, like a single-song MP3. Although the authors don't say so explicitly, my understanding is that the scheme is only useful on commercial p2p distribution systems that adopt the proposed protocol."