Fruit machine was a slang term for a device that was supposed to be able to identify homosexuals. The subjects were made to view pornography, and the device measured the pupils of the eyes, perspiration, and pulse for a supposed erotic response.
The fruit machine was employed in Canada in the 1950s and 1960s during a campaign to eliminate all homosexuals from the civil service, the RCMP, and the military. A substantial number of workers did lose their jobs. Although funding for the "fruit machine" project was cut off in the late 1960s, the investigations continued, and the RCMP collected files on over 9 000 suspected gay men and lesbians.
Fruit Machine is also a British term for a slot machine.