MK-ULTRA, which operated from the 1950s until the early '60s, was created and run by a chemist named Sidney Gottlieb. Journalist Stephen Kinzer, who spent several years investigating the program, calls the operation the "most sustained search in history for techniques of mind control."

Some of Gottlieb's experiments were covertly funded at universities and research centers, Kinzer says, while others were conducted in American prisons and in detention centers in Japan, Germany and the Philippines. Many of his unwitting subjects endured psychological torture ranging from electroshock to high doses of LSD, according to Kinzer's research.

"Gottlieb wanted to create a way to seize control of people's minds, and he realized it was a two-part process," Kinzer says. "First, you had to blast away the existing mind. Second, you had to find a way to insert a new mind into that resulting void. We didn't get too far on number two, but he did a lot of work on number one."