Britain's surveillance agency GCHQ, with aid from the US National Security Agency, intercepted and stored the webcam images of millions of internet users not suspected of wrongdoing, secret documents reveal. GCHQ files dating between 2008 and 2010 explicitly state that a surveillance program codenamed Optic Nerve collected still images of Yahoo webcam chats in bulk and saved them to agency databases, regardless of whether individual users were an intelligence target or not. 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. Yahoo ... denied any prior knowledge of the program, accusing the agencies of a whole new level of violation of our users' privacy". Optic Nerve, the documents provided by NSA whistleblower Edward Snowden show, began as a prototype in 2008 and was still active in 2012. The system, eerily reminiscent of the telescreens evoked in George Orwell's Nineteen Eighty-Four, was used for experiments in automated facial recognition, to monitor GCHQ's existing targets, and to discover new targets of interest. Such searches could be used to try to find terror suspects or criminals making use of multiple, anonymous user IDs. Rather than collecting webcam chats in their entirety, the program saved one image every five minutes from the users' feeds ... to avoid overloading GCHQ's servers. The documents describe these users as "unselected" - intelligence agency parlance for bulk rather than targeted collection.