How the Stasi network operated
The Ministry for State Security (MfS) was established in 1950 as the "sword and shield" of East Germany's ruling Socialist Unity Party (SED).
The notoriety of the MfS stems from its domestic service, known as the Stasi, which operated a network of 250,000 full-time and "inofficial" informers (IM) to spy on fellow East German citizens.
The Stasi ran one informer for every 68 people, a higher concentration of agents than the Gestapo or the KGB, and had amassed 17 million files filling 178 km of shelving by the time it was disbanded. When civil rights protesters stormed the MfS headquarters in Berlin in January 1990, they found officials worked feverishly to destroy the files.
The MfS' foreign service was headed by the late Markus Wolf, famed for his "Romeo" agents, who befriended lonely secretaries of high-ranking West German officials and for planting a spy as adviser to West German chancellor Willy Brandt in the 1970s.
About 500,000 pages of these files have been reconstructed, but just 250 sacks out of a total of 16,000 sacks of shredded material have been recovered. New scanning technology has been introduced and is expected to reduce the processing time from an estimated 400 years to less than 10.
Since 1991, over 2.3 million Germans have viewed personal files containing everything from banal reports on the distant past to painful revelations about relatives and friends.