The Lives of Others is a masterful Florian Henckel von Donnersmarck film about the Stasi, the East German secret police force, during the final days of the Communist government. I highly recommend that you see it if you have the chance.
This Roger Boyes/Times article about the movie passes along Alex Latotzky’s clever observation, which you will understand perfectly once you see the movie:

“Some ex-Stasi became taxi drivers, and very good ones, too; you just had to give your name and they knew the address.”