" Green had been amazed by their discovery: you could break into a Titan II complex with just a credit card. Once the officers showed him how to do it, Green requested permission to stage a black hat operation at 4-7—an unannounced demonstration of how someone could sneak into the launch control center undetected. SAC had a long history of black hatting to test the security at its facilities. Black hat teams would plant phony explosives on bombers, place metal spikes on runways, infiltrate a command post and then hand a letter to the base commander that said, “You’re dead. "

― Eric Schlosser , Command and Control: Nuclear Weapons, the Damascus Accident, and the Illusion of Safety