By the 1970s, the Stasi had decided that the methods of overt persecution that had been employed up to that time, such as arrest and torture, were too crude and obvious. It was realised that psychological harassment was far less likely to be recognised for what it was, so its victims, and their supporters, were less likely to be provoked into active resistance, given that they would often not be aware of the source of their problems, or even its exact nature. Zersetzung was designed to side-track and "switch off" perceived enemies so that they would lose the will to continue any "inappropriate" activities.
Top Secret is a timely rejoinder to those who argue that the NSA is a necessary evil, and it’s even more timely in light of the revelation that the NSA targeted German Chancellor Angela Merkel for eavesdropping. The US is not East Germany, and the NSA is not the Stasi, but they share a common taproot of fear. While the NSA may not resort to the Stasi’s cruelest methods, it lords over one of the most sophisticated and pervasive intelligence apparatuses on the planet. Would it be surprising if, decades from now, someone found similar relics in the NSA archive?