By Julia Fioretti LONDON (Reuters) – Britains spy agency GCHQ intercepted millions of peoples webcam chats and stored still images of them, including sexually explicit ones, the Guardian newspaper reported on Thursday. GCHQ files dating between 2008 and 2010 provided to the newspaper by the former U.S. National Security Agency (NSA) contractor Edward Snowden, revealed that the surveillance program, codenamed Optic Nerve, saved one image every five minutes from randomly selected Yahoo Inc webcam chats and stored them on agency databases. Optic Nerve, which began as a prototype in 2008 and was still active in 2012, was intended to test automated facial recognition, monitor GCHQs targets and uncover new ones, the Guardian said. It said that under British law, there are no restrictions preventing images of U.S. citizens being accessed by British intelligence.