The Stasi complex on Normannenstrasse in the Lichtenberg district consisted of 41 brown concrete buildings. In addition, the Stasi possessed 1,181 safe houses, 305 vacation homes, 98 sports facilities, and 18,000 apartments for meetings with spies. The Stasi had a budget of 4 billion East German marks. It had 97,000 full-time employees—after the army, it was East Germany’s largest employer. There were 2,171 mail readers, 1,486 phone tappers, and another 8,426 people who monitored phone conversations and radio broadcasts. In addition, there were about 110,000 active unofficial collaborators and perhaps ten times that many occasional informants. The Stasi kept files on 6 million people. There were 39 separate departments—even a department to spy on other Stasi members. A master file with a single card for each Stasi employee, collaborator, and object of surveillance stretches for more than a mile—the cards for people named Müller alone reach a hundred yards. Stacked up, the Stasi’s complete files reached 125 miles. They weighed fifty tons per mile; in total, 62,500 tons.