Ascent Capital Group, Inc. is a public holding company whose primary subsidiary is Monitronics. Ascent Media was a wholly owned subsidiary of the Discovery Holding Company. DHC spun off Ascent Media as an independent, public company on September 17, 2008. The company's main activity through its wholly owned subsidiary, Monitroincs, is to provide security alarm monitoring services to more than 1 million residential and commercial customers in the United States, Canada and Puerto Rico through its nationwide network of independent dealers. In its past, Ascent Capital Group provided creative and technical services to the media and entertainment industries. Ascent Media was a wholly owned subsidiary of the Discovery Holding Company. DHC spun off Ascent Media as an independent, public company on September 17, 2008. The assets and operations of Ascent Capital Group are composed primarily of the assets and operations of various businesses acquired from 2000 through 2004, including The Todd-AO Corporation, Four Media Company, Video Services Corporation, Group W Network Services, London Playout Centre and the systems integration business of Sony Electronics. The combination and integration of these and other acquired entities allows AMG to offer integrated outsourcing for the technical and creative requirements of its clients, from content creation and other post-production services to media management and transmission of the final product to broadcast television stations, cable system head-ends and other destinations and distribution points."