The telescreen received and transmitted simultaneously. Any sound that Winston made, above the level of a very low whisper, would be picked up by it, moreover, so long as he remained within the field of vision which the metal plaque commanded, he could be seen as well as heard. ~ 1984A Pennsylvania school district issued laptop webcams to their students. Those webcams could be activated remotely so school officials could watch the students while they were at home and discipline students for inappropriate conduct what at home.
It was even conceivable that they watched everybody all the time. But at any rate they could plug in your wire whenever they wanted to. You had to live -- did live, from habit that became instinct -- in the assumption that every sound you made was overheard, and, except in darkness, every movement scrutinized. ~ 1984Apple Is Their Ad
Remember that Apple ad that was a takeoff on 1984. Well Apple is getting there. The have applied for a patent on a system that would require customers to watch advertising over, say, the iPad. If people don't watch and don't respond correctly proving that they are watching the product would cease working until the ad is properly viewed. The system will punish people who are not sufficiently responsive.
These tests “can be made progressively more aggressive if the user has failed a previous test,” the application says. One option makes the response box smaller and smaller, requiring more concentration to find and banish. Or the system can require that the user press varying keyboard combinations, the current date, or the name of the advertiser upon command, again demonstrating “the presence of an attentive user.” ~ New York TimesApple Is Watching.