Peter Taylor, Howard Bradburn, Ceri Thomas: Edward Snowden: Spies and the Law. In: BBC Panorama. 10. Oktober 2015, abgerufen am 11. November 2015 (englisch).
Spencer Ackerman, James Ball: Optic Nerve: millions of Yahoo webcam images intercepted by GCHQ. In: The Guardian. 28. Februar 2014, abgerufen am 9. März 2014 (englisch): „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.“
Duncan Campbell: Big Brother is born. And we find out 15 years too late to stop him. In: The Register. 16. September 2015, abgerufen am 18. Dezember 2015 (englisch): „PRESTON works alongside and links to massive databases holding telephone call records, internet use records, travel, financial, and other personal records held by the National Technical Assistance Centre (NTAC)“
