The East German Ministry of State Security, popularly known as the Stasi, was one of the largest and most intrusive secret police systems in world history. So extensive was the system of surveillance and control that in any given year throughout the 1970s and 1980s, about one in fifty of the 13 million East German adults were working for the Stasi either as an officer or as an informer. Drawing on original sources from the Stasi archives...