I was always creeped out about the possibility of this with the Kinect, which is why it is in the closet now.
Originally Posted by Gamespot
A patent application by Microsoft for "Content Distribution Regulation by Viewing User" has surfaced. The filing, which was made with the US Patent and Trademark Office on April 26, 2011, and was spotted by Eurogamer, outlines a system designed to monitor viewers as they watch; ensuring compliance with licensing for music, games, and film.
The technology works by using cameras (no explicit mention is made of the Kinect or a Kinect successor) found in home and mobile devices to take still or moving images of the consumers and their environment. The system then compares the number of viewers visible in the frame with the licensing terms attached to the product; prompting watchers to purchase additional licenses (as required) for each person watching.
Rest of the article here.