Many people in the GDR still feared the Ministry of State Security, which was known as the "Stasi". Modrow renamed the Ministry into "Amt für Nationale Sicherheit" ("Office of National Security"; AfN). The AfN started to destroy the documents which they had collected over the years. The oppositional forces wanted the documents to be kept, and so they occupied all the Stasi offices in the country in December 1989 and January 1990. The last was the Stasi headquarters in East Berlin on 15 January 1990.