Optic Nerve is a mass surveillance program run by the British signals intelligence agency Government Communications Headquarters (GCHQ), with help from the US National Security Agency, that surreptitiously collects private webcam still images from users while they are using a Yahoo! webcam application. As an example of the scale, in one 6-month period, the program is reported to have collected images from 1.8 million Yahoo! user accounts globally. The program was first reported on in the media in February 2014, from documents leaked by the former National Security Agency contractor Edward Snowden, but dates back to a prototype started in 2008, and was still active in at least 2012.