What if at the beginning of the game, it asked you if it was acceptable to share information recorded during the game with other people on your friends list. You hit OK without thinking about or reading through the terms (cuz who even DOES that, right?).
The game manufactures moments where you have to look intently at the subscreen. Maybe you need to do some puzzles or whatnot. It would be a great way to deliver shock scares. Like you're asked to look at one part of the screen intently and something pops up and shocks you. OR, since you'll be focused so intently on the subscreen, you don't notice the TV screen has changed and there are big old creepy eyes staring at you. The effect would be triggered to fade away once you put down the subscreen. The game could also fiddle with the volume settings on the screen. Regardless of whether you put down the volume, it would have whispers or faint voices coming through the controller speakers.
The big thing is though it would actually record your face while you performed those subscreen puzzles. It would be all to easy to record precisely when you get freaked out by shock scares because it would be preset moment determined by the game.
THEN, the game sends those short clips to other people on your friends list playing the game, and their clips get sent to you. Then, every so often, you would look into some reflective surface in the game or water or whatever and the game would put in faded out images and clips of your friends, often with expressions of shock or terror. It would be clear enough to be recognizable as someone you know but faint enough for you to question whether or not you really saw a face in that mirror.
edit: oh yeah, and the game could fuck with the fact that you accepted the terms of service without reading thoroughly. Like one time you boot up the game and it randomly tells you you've been billed a significant amount for some made up DLC. You're like WHAT? What the hell??! And it says you agreed to it in the ToS.