Surveilllance without a warrant has been in the news recently. Much of the discussion centers on surveillance allowed under the Foreign Intelligence Surveillance Act. Below is text from the law relating to warrantless surveillance.
§ 1802. Electronic surveillance authorization WITHOUT COURT ORDER; certification by Attorney General; reports to Congressional committees; transmittal under seal; duties and compensation of communication common carrier; applications; jurisdiction of court.
(1) Notwithstanding any other law, the President, through the Attorney General, may authorize electronic surveillance without a court order under this subchapter to acquire foreign intelligence information for periods of up to one year if the Attorney General certifies in writing under oath that—
(A) the electronic surveillance is solely directed at—
(i) the acquisition of the contents of communications transmitted by means of communications used exclusively between or among foreign powers, as defined in section 1801 (a)(1), (2), or (3) of this title;
(ii) the acquisition of technical intelligence, other than the spoken communications of individuals, from property or premises under the open and exclusive control of a foreign power, as defined in section 1801 (a)(1), (2), or (3) of this title;
(B) there is no substantial likelihood that the surveillance will acquire the contents of any communication to which a United States person is a party;
(C) the proposed minimization procedures with respect to such surveillance meet the definition of minimization procedures under section 1801 (h) of this title;
if the Attorney General reports such minimization procedures and any changes thereto to the House Permanent Select Committee on Intelligence and the Senate Select Committee on Intelligence at least thirty days prior to their effective date, unless the Attorney General determines immediate action is required and notifies the committees immediately of such minimization procedures and the reason for their becoming effective immediately.
(2) An electronic surveillance authorized by this subsection may be conducted only in accordance with the Attorney General’s certification and the minimization procedures adopted by him. The Attorney General shall assess compliance with such procedures and shall report such assessments to the House Permanent Select Committee on Intelligence and the Senate Select Committee on Intelligence under the provisions of section 1808 (a) of this title.
(3) The Attorney General shall immediately transmit under seal to the court established under section 1803 (a) of this title a copy of his certification. Such certification shall be maintained under security measures established by the Chief Justice with the concurrence of the Attorney General, in consultation with the Director of Central Intelligence, and shall remain sealed unless—
(A) an application for a court order with respect to the surveillance is made under sections 1801 (h)(4) and 1804 of this title;
(B) the certification is necessary to determine the legality of the surveillance under section 1806 (f) of this title.
(4) With respect to electronic surveillance authorized by this subsection, the Attorney General may direct a specified communication common carrier to—
(A) furnish all information, facilities, or technical assistance necessary to accomplish the electronic surveillance in such a manner as will protect its secrecy and produce a minimum of interference with the services that such carrier is providing its customers;
(B) maintain under security procedures approved by the Attorney General and the Director of Central Intelligence any records concerning the surveillance or the aid furnished which such carrier wishes to retain.
The Government shall compensate, at the prevailing rate, such carrier for furnishing such aid.
(b) Applications for a court order under this subchapter are authorized if the President has, by written authorization, empowered the Attorney General to approve applications to the court having jurisdiction under section 1803 of this title, and a judge to whom an application is made may, notwithstanding any other law, grant an order, in conformity with section 1805 of this title, approving electronic surveillance of a foreign power or an agent of a foreign power for the purpose of obtaining foreign intelligence information, except that the court shall not have jurisdiction to grant any order approving electronic surveillance directed solely as described in paragraph (1)(A) of subsection (a) of this section unless such surveillance may involve the acquisition of communications of any United States person.