in june 1999, napster was released as an unstructured centralized peer-to-peer system, requiring a central server for indexing and peer discovery. it is generally credited as being the first peer-to-peer file sharing system. in december 1999, napster was sued by several recording companies and lost in "a&m records, inc. v. napster, inc.". in the case of napster, it has been ruled that an online service provider could not use the "transitory network transmission" safe harbor in the dmca if they had control of the network with a server.