GCHQ operated a secret surveillance project called Optic Nerve which captured images from millions of Yahoo! webcam chats made between people suspected of no crime.
Leaked documents dated from 2008 to 2010 reveal that Yahoo! was chosen because it was known to be used by “GCHQ targets”. The NSA was also involved, providing software to identify video traffic online and make screenshots searchable once intercepted.
The images were collected from 1.8 million Yahoo! accounts around the world to conduct experiments in facial recognition and to detect criminals or terror suspects who were using multiple accounts to hold webcam chats.
The Guardian, which has access to the leaked documents supplied by former NSA contractor Edward Snowden, reports that one image was taken every five minutes, partly to satisfy human rights legislation and partly to avoid being overwhelmed with huge swathes of data.
The documents say that the victims of the intrusion were “unselected”, which is a term used to describe randomly selected individuals rather than those suspected of wrongdoing.
The newspaper reports that one document says: "Face detection has the potential to aid selection of useful images for 'mugshots' or even for face recognition by assessing the angle of the face. The best images are ones where the person is facing the camera with their face upright."
Agents were reportedly not able to trawl the images at random but could search for images from users with similar account names to known suspects. The documents were taken from GCHQ’s internal wiki and say that the project was currently closed but “shortly to return!”
Files reveal that GCHQ inadvertently intercepted pornographic images with the project: "Unfortunately … it would appear that a surprising number of people use webcam conversations to show intimate parts of their body to the other person. Also, the fact that the Yahoo software allows more than one person to view a webcam stream without necessarily sending a reciprocal stream means that it appears sometimes to be used for broadcasting pornography."
Between 3pc and 11pc of images intercepted by the security agency was thought to be pornographic, according to internal documents. It appears that documents intended for analysts reminded them that “dissemination of offensive material is a disciplinary offence” at GCHQ.
Yahoo! issued a statement to the Guardian on the project: "We were not aware of, nor would we condone, this reported activity. This report, if true, represents a whole new level of violation of our users' privacy that is completely unacceptable, and we strongly call on the world's governments to reform surveillance law consistent with the principles we outlined in December.
"We are committed to preserving our users' trust and security and continue our efforts to expand encryption across all of our services.”