Top secret files on unidentified flying objects (UFOs) were declassified by the U.S. National Security Agency (NSA) as a result of a 1980 civil action suit brought against the agency by a group named Citizens Against Unidentified Flying Objects Secrecy.
Epoch Times has gone through the communications intelligence reports to collect some interesting tidbits.
Much of the text is heavily redacted, making it hard to glean much information.

An example of a heavily redacted report. NSA