How much control is necessary for a society to function and how can the example of the Stasi help us understand today’s situation with policing, surveillance and big data? The Ministry for State Security of the GDR, the Stasi (1950-1990) is known as one of the most effective and repressive secret police agencies of our time. Stasi collaborators permeated GDR society and in addition to exerting psychological trauma on people under investigation, this vast network of informants collected over 111 kilometers (69 miles) of documents (written notes, photos, slides, flim and sound recording). Social control existed on the other side of the border too, with intelligence agencies in the FRG collecting data on citizens.