Napster was the first major peer-to-peer file sharing system, launched in 1999, allowing users to share MP3 files. It grew to over 20 million users but faced legal issues for copyright infringement. The Pirate Bay, founded in 2003, is another major torrent site that has faced repeated legal challenges and raids over the years for facilitating copyright infringement. Limewire was a popular P2P program that distributed music and was shut down in 2010 due to a court injunction. These systems helped spread digital piracy but also faced major legal backlash from the music industry.