Major owners of copyright materials -- including movie studios, record labels, software and entertainment companies -- all routinely use "sniffers" (technology that detects patterns of computer use that are consistent with downloading and sharing movies, songs and other content). The interests of these copyright owners are protected by trade and advocacy organizations like the MPAA and RIAA.
The MPAA (Motion Picture Association of America) is an advocacy organization that represents the American motion picture, home video and television industries. The association supports strong legal protection of audio/visual works and fights copyright infringement around the world. It promotes the adoption of more protective federal copyright legislation, and also seeks to educate students, parents and teachers about copyright protection and awareness. More information is available at its website. See: http://www.mpaa.org/
The RIAA (Recording Industry Association of America) is a trade association that represents the U.S. recording industry. Its stated mission is to assist the recording industry to thrive, which includes advocating for changes in the federal copyright laws, and taking action to protect copyrights against piracy and infringement. The RIAA has been very active in attempting to monitor and stop illegal music down-loading on campuses. See: http://www.riaa.com