The Copyright Alert System (CAS) is a private system for alerting and punishing internet subscribing customers of AT&T, Cablevision, Time Warner, Verizon and Comcast in regards to accusations of bit torrent use via their home networks to access alleged copyrighted material from a list of specific entertainment corporations and their CAS registered content. It is limited to customers of those internet vendors in the United States. The consortium that manages the program has branded it as the "six strikes program."