"In one six-month period in 2008 alone, the agency collected webcam imagery – including substantial quantities of sexually explicit communications – from more than 1.8 million Yahoo user accounts globally," the Guardian reports, before noting that this operation (codenamed "Optic Nerve") was only one of the agency's attempts at biometric recognition via consumer camera technology.
A separate GCHQ project explored the possibility of gathering images from the Kinect peripheral. "[O]ne presentation discusses with interest the potential and capabilities of the Xbox 360's Kinect camera, saying it generated 'fairly normal webcam traffic' and was being evaluated as part of a wider program." It's unclear if GCHQ ever attempted to intercept Kinect data on a large scale, but as The Guardian points out, the idea isn't entirely novel. Earlier documents published by the paper detail similar exploratory efforts by the American NSA.