Do you know what the Stasi was? It was the East German secret police who, in the tradition of all communist / fascist regimes, tormented its populace.
Now, nearly 20 years after the two Germanys were rejoined, a group of people are trying to piece together the shredded, burned and otherwise damaged files of people persecuted, tortured and killed by the Stasi.
You can read more about the effort here.
If you want to see a movie about the persecution in East Germany, I suggest the excellent "The Lives of Others" which won a much-deserved Oscar and a butt-load of other awards because it is, like, one of the best movies of the millennium.