The realization of the market for downloadable music grew widespread with the development of Napster, a music and file sharing service created by Shawn Fanning that made a major impact on the Internet scene during the year 2000. Some services have tethered downloads, meaning that playing songs requires an active membership. Napster was founded as a pioneering peer-to-peer (P2P) file sharing Internet service that emphasized sharing audio files, typically music, encoded in MP3 format. The original company ran into legal difficulties over copyright infringement, ceased operations and was eventually acquired by Roxio. In its second incarnation Napster became an online music store until it was acquired by Rhapsody from Best Buy on December 1, 2011. Later companies and projects successfully followed its P2P file sharing example such as Gnutella, Freenet, Kazaa, Bearshare, and many others. Some services, like LimeWire, Scour, Grokster, Madster, and eDonkey2000, were brought down or changed due to similar circumstances.