Clouds of Secrecy: The Army's Germ Warfare Tests Over Populated Areas (1988)

In the 1970s, Americans learned that for decades they had been unsuspecting guinea pigs in a series of astonishing experiments conducted by the U.S. Army. Military researchers had been secretly spraying clouds of bacteria over populated areas in order to study America's vulnerability to biological weapons. No precautions were taken to protect the millions of people exposed, despite known risks to their health.