Black helicopter

The term black helicopter refers to conspiracy theories and conspiracy theorists. It became popular with the militia movement in the 1990s as a warning sign that there would be a military takeover of part or all of the U.S. Of course, one of the prime targets for conspiracy theorists (and people on the Right in general) is the UN, so they'd cook up rumors that the UN patrolled the United States with black helicopters ready to take the country over.

The most media attention black helicopters received was in 1995 via freshman Republican Idaho Representative Helen Chenoweth. She claimed to The New York Times that some of her constituents spotted armed federal agents who landed black helicopters on the ranches of Idaho farmers to enforce the Endangered Species Act.

Yeah, you gotta love (and by love I mean hate) conspiracy theorists.