Thousands of documents released under FOIA also indicate that many U.S. intelligence agencies collected (and still collect) information on UFOs, including the Defense Intelligence Agency (DIA), FBI, CIA, National Security Agency (NSA), as well as military intelligence agencies of the Army and Navy, in addition to the Air Force.[46]
The investigation of UFOs has also attracted many civilians, who in the U.S formed research groups such as National Investigations Committee On Aerial Phenomena (NICAP, active 1956–1980), Aerial Phenomena Research Organization (APRO, 1952–1988), Mutual UFO Network (MUFON, 1969–), and Center for UFO Studies (CUFOS, 1973–).
http://en.wikipedia.org/wiki/Ufo
