After the september 11 attacks, who authorized the national security agency (nsa) to listen to domestic telephone conversations without a court warrant

After September 11, the government intensified their surveillance on foreign and domestic entities. The Foreign Intelligence Surveillance Act (FISA) sanctioned warrantless electronic surveillance of individuals outside of the United States, as well as U.S. citizens as long as there was permission from the FISA court. In October 2001, President George W. Bush secretly granted authority to the National Security Agency (NSA) to gather Web, email and telephone records.