@Bas: A severe lack of brain power?
It has passive input and it's always on -> it can be used to constantly monitor you. Of course, my cellphone has a camera and a mic, and so does my laptop - why is it more likely that a gaming console would spy on you and not those devices that are far more connected to your personal life. among other things?
Forget about worrying about smart TVs and Xboxes potentially invading your privacy when you're in the living room watching TV, and start worrying about the phone in your pocket that you (and your wife and your daughter) probably have on, watching, listening and connected when you're in the bedroom, the bathroom and the boardroom.