UFO conspiracy theory

A UFO conspiracy theory is any one of many often overlapping conspiracy theories which argue that evidence of the reality of unidentified flying objects is being suppressed by the governments. Such theories are often intentionally hoaxed, and are backed by little or no evidence, and absolutely no reliable evidence despite significant research on the subject by non-governmental scientific agencies, and therefore, are considered pseudoscience. 

They commonly argue that Earth governments, especially the Government of the United States, are in communication or cooperation with extraterrestrials despite public claims to the contrary. The theory's tendency to target the United States government over others is likely because it is an American cultural phenomenon. Some of these theories claim that the government is explicitly allowing alien abduction.