Under Operation Midnight Climax, the CIA set up fake brothels to drug unsuspecting citizens and watch them through two-way mirrors.

This was one of the most extreme parts of the project. The CIA hired prostitutes to lure ordinary men to secret safe houses in San Francisco. Once there, the men were secretly slipped LSD. CIA agents sat behind two-way mirrors, sipping cocktails, and watching how the men reacted to the drug. The rooms were wired with hidden microphones disguised as regular wall outlets. The victims never knew they were government guinea pigs.