The phrase "black helicopters" is commonly used to describe a conspiracy theory where people believe that secret military or government helicopters are secretly surveilling or controlling them. Full definition
Mom says Cherie's mental state deteriorated fast after her boyfriend / cocaine connection dumped her, and soon she was seeing black helicopters following her, international conspiracies spying on her. (bookbrowse.com)
But if the DEA decides marijuana is still a Schedule I drug, Baer says the agency will not be dropping down into Colorado, Washington, and Oregon from black helicopters and arresting everyone. (inc.com)
Wasn't the Russian's suppose to take over the USA with black helicopters and black tanks with all kinds of soldiers dressed in black when we turned year 2000? (religion.blogs.cnn.com)