The technique would be similar to technology already being used to track and prevent copying of music files on some university networks. Philips' audio fingerprinting technology is central to Napster founder Shawn Fanning's new company Snocap, which aims to turn file-swapping networks into digital-song stores.More info at Cnet
Philips developing technology to protect digital-video

Philips is developing a new "fingerprinting" technlogy aimed to block the transfer of copyrighted digital-video files on the internet.