The Player of Games (Culture, #2)

by Iain M. Banks

But how can you have a secret policeman? I thought one of the points of having a uniform for the police was so that they could be easily identified and act as a deterrent.” “Good grief,” Za said, covering his face with his hands. He put them down and gazed at Gurgeh. He took a deep breath. “Right… well; the secret police are people who go about listening to what people say when they aren’t being deterred by the sight of a uniform. Then if the person hasn’t actually said anything illegal, but has said something they think is dangerous to the security of the Empire, they kidnap them and interrogate them and—as