"It was terribly dangerous to let your thoughts wander when you were in any public place. .. The smallest thing could give you away. A nervous tic, an unconscious look of anxiety, a habit of muttering to yourself -- anything that carried with it the suggestion of abnormality, of having something to hide. In any case, to wear an improper expression on your face .. was itself a punishable offence. There was even a word for it in Newspeak: facecrime, it was called."
-George Orwell, 1984