Music piracy involves the unauthorized copying and distribution of music, movies, books and other media in digital form. It occurs through downloading from websites and peer-to-peer file sharing programs. Music piracy happens because people can get music for free instead of paying. This costs the music industry millions each year through lost sales. Peer-to-peer programs like Napster and BitTorrent have enabled widespread music piracy by making large libraries of music easily available to share between users.