“Signals intelligence” is defined in the DEPARTMENT OF DEFENSE DICTIONARY OF MILITARY AND
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ASSOCIATED TERMS, Joint Publication 1-02 (April 12, 2001), as follows:
1. A category of intelligence comprising either individually or in combination all
communications intelligence, electronic intelligence, and foreign instrumentation signals
intelligence, however transmitted. 2. Intelligence derived from communications,
electronic, and foreign instrumentation signals. Also called SIGINT. . . .
Id. at 390 (cross-references omitted). “Communications intelligence” is defined as “Technical
information and intelligence derived from foreign communications by other than the intended
recipients. Also called COMINT.” Id. at 84. “Electronic intelligence” is defined as “Technical and
geolocation intelligence derived from foreign non-communications electromagnetic radiations
emanating from other than nuclear detonations or radioactive sources. Also called ELINT. . . .” Id.
at 140 (cross-references omitted). “Foreign instrumentation signals intelligence” is defined as:
Technical information and intelligence derived from the intercept of foreign
electromagnetic emissions associated with the testing and operational deployment of non-
US aerospace, surface, and subsurface systems. Foreign instrumentation signals
intelligence is a subcategory of signals intelligence. Foreign instrumentation signals
include but are not limited to telemetry, beaconry, electronic interrogators, and video data
links. Also called FISINT. . . .
Id. at 167 (cross-references omitted).
James Risen and Eric Lichtblau, Bush Lets U.S. Spy on Callers Without Courts, N.Y. TIMES, Dec.
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16, 2005, at 1, 22 (citing anonymous government officials to report that the executive order, which
allows some warrantless eavesdropping on persons inside the United States, “is based on classified
(continued...)
Congressional Research Service Washington, D.C. 20540-7000
CRS prepared this memorandum to enable distribution to more than one congressional client.
Memorandum January 5, 2006
SUBJECT: Presidential Authority to Conduct Warrantless Electronic
Surveillance to Gather Foreign Intelligence Information
FROM: Elizabeth B. Bazan and Jennifer K. Elsea
Legislative Attorneys
American Law Division
Recent media revelations that the President authorized the National Security Agency
(NSA) to collect signals intelligence from communications involving U.S. persons within
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the United States, without obtaining a warrant or court order, raise numerous questions
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