I've just read Orwell's 1984 (finally). There is an episode there: "Winston covered his face with his hands. 'Smith! Prisoner 6079!' yelled the telescreen, 'Unc

I've just read Orwell's 1984 (finally). There is an episode there: "Winston covered his face with his hands. 'Smith! Prisoner 6079!' yelled the telescreen, 'Uncover your face! No faces covered in the cells!" The Big Brother wants to see expressions on your face at all times, and encryption lets you cover it when you have ungood thoughts.