Unit 8341 was the elite military force created by PLA(People's Liberation Army) military commander Wang Dongxing for the purpose of protecting China's top leaders. Also called the Beijing Security Regiment, Unit 8341 was the Secret Service on crack, reporting directly to Wang, conducting all of the secret arrests, information suppressions, and political oppressions characteristic of good old Red Commie China. Not to be neglected is their prestigious task of protecting jolly old Chairman Mao.
Wang, then a seventeen year old orphaned peasant, had joined Mao Ze Dong's Jiangxi Soviet in 1933 and was fanatically loyal to Mao ever since. His rise through the military ranks probably owed as much to his connections with Mao as any political acumen. Not much information exist on him, any that exists probably obscured and hidden on purpose. One could justifiably say he was one of the innumerable grey men of history, controlling the world from behind the scenes.
With the creation of the secret police force, and his numerous high ranking official security positions, Wang possessed inordinate political power over Beijing, where all the important people were anyway. Unit 8341 oversaw the arrests and confinements of numerous Cultural Revolution victims, including Deng Xiaoping. Wang himself allegedly broke news of Lin Biao's plot to against Mao.
As an example of the enormous power wielded by Wang Dongxing through Unit 8341, it was responsible for the arrest of the Gang of Four in 1976, Wang believing that Mao had intended Hua Guofeng to be the next party chairman.
Unit 8341 also had the job of "pacifying" the most militant factories and universities occuppied by the Red Guard in Beijing after Mao decided that the Cultural Revolution had become too chaotic for his tastes.
Sources: Jonathan D. Spence, The Search for Modern China. New York: WW Norton & Company, 1999.
And of course, Google