During the Korean War,
Korean and Chinese captors reportedly brainwashed American POWs held in prison camps. Several prisoners ultimately confessed to waging germ warfare -- which they hadn't -- and pledged allegiance to communism by the end of their captivity. At least 21 soldiers refused to come back to the United States when they were set free. It sounds impressive, but skeptics point out that it was 21 out of more than 20,000 prisoners in communist countries.