Indeed. This reminds me of "Larson Localizers" [1] from Vernor Vinge's "A Deepness in the Sky":

  "Among the unsuspecting, they are an espionage miracle.
   Abused, they lead to ubiquitous law enforcement, and a
   quick end to civilization."

1: http://en.wikipedia.org/wiki/A_Deepness_in_the_Sky#Localizer...