GCHQ, Britain's spy agency intercepted millions of Yahoo's webcam chats, which included sexually explicit ones.
As per the records of GCHQ files (2008 – 2010) maintained by the U.S. National Security Agency (NSA) contractor Edward Snowden, revealed that the surveillance programme, codenamed Optic Nerve, saved one image every five minutes from randomly selected Yahoo Inc webcam chats and stored them on agency databases.
Optic Nerve, was able to test automated facial recognition, monitor GCHQ's targets and uncover new ones. GCHQ collected images from the webcam chats of more than 1.8 million users globally in a six-month period in 2008. GCHQ also tried to limit its staff's ability to see the webcam images, but they could still see the images of people with similar usernames to intelligence targets.
The Guardian newspaper also reported that under the British law, there are no restrictions preventing images of U.S. citizens being accessed by British intelligence.
The U.S. and British spy agencies also stated that the webcam information was fed into the NSA's search tool and all of the policy documents were available to NSA analysts.
GCHQ also implemented restrictions on the collection of sexually explicit images, but its software was not always able to distinguish between these and other images.
The spy agency eventually excluded images in which the software had not detected any faces from search results to prevent staff from accessing explicit images.
