Obtain a warrant to search for terrorists

Wiretaps

United States Foreign Intelligence Surveillance Court was created in 1978.

Conduct warrantless searches in the interest of national security

FISA stands for the Foreign Intelligence Surveillance Act. It was signed in 1978 as an Act of Congress by President Jimmy Carter. It prescribes procedures for the physical and electronic surveillance and collection of "foreign intelligence information" between "foreign powers" and "agents of foreign powers". It may include American citizens suspected of being engaged in espionage and violating U.S. law on territory under United States control. It doesn't apply outside the U.S.