The state security service of the GDR did not only control their opponents but was also present in the everyday life of the majority: as surveillance apparatus, as undercover authority, as a taboo myth. The articles describe and analyse the influence of the secret police in companies, schools and villages. The authors give insights in state security files, try to find memories in the lives of GDR citizens and draw comparisons between Stalinism and the NS-dictatorship. The scale and limits of a preventive security doctrine of a regime that never trusted its own citizens are supported by various sources and is carried out methodically with due care.