The leaked NSA Inspector General report detailing the history of the domestic spying program reveals that on this day NSA Director General Mike Hayden began approaching telecommuncations companies to voluntarily give the government data. As the report states, "General Hayden stated that the National Security Agency and Federal Bureau of Invsetigation required their assistance 'to collect intelligence vital to the national security arising from the events of 11 September 2001,' and specifically requested that they 'provide survey, tasking and collection against international traffic, some of which terminates in the United States; provide aggregated call record information; and supply computer to computer data which can be used to determine the communicants.' Their assistance was 'needed to identify members of international terrorist cells in the United States and prevent future terrorist attacks against the United States.' These first letters also stated that the request was authorized by the President with the legal concurrence of the Attorney General, pursuant to Article II of the Constitution."
Leaked NSA Inspector General Report, Pg 31