Copyright Alert System
By Dan Nosowitz:
"The Copyright Alert System, or CAS, is a system developed by internet service providers (ISPs include Comcast, Verizon, and Time Warner) and copyright holders (largely the Motion Picture Association of America, the Recording Industry Association of America, and the National Cable and Telecommunications Association, the trade organizations that represent the movie, music, and television industries, respectively) to battle online piracy. The approach to battling copyright infringement before now has been piecemeal and vague--sometimes you'd get a letter telling you to stop, sometimes you'd get sued for billions of dollars, and, usually, absolutely nothing would happen--and the CAS is an effort to standardize a response to piracy.
The internet providers and copyright holders have begun using peer-to-peer (P2P) surveillance methods to try to sniff out when copyrighted content is uploaded or shared illegally. A company called MarkMonitor has been contracted to join BitTorrent networks (the most common way to illegally share files) and search for the names of copyright-protected movies, music, and TV shows. The list of those names is provided by the MPAA, RIAA, and NCTA. When MarkMonitor finds a file in violation, they snag the IP address of the user who's sharing the file and send it off to that user's internet provider, who issues a series of escalating warnings." ([http://www.popsci.com/node/70921/)