(27. Februar 2014) The surveillance effort operated by Britain’s Government Communications Headquarters, or GCHQ, was code-named Optic Nerve. Images from Yahoo webcam chats were captured in bulk through the agency’s fiber-optic cable taps and saved to a GCHQ database.

It is unclear how much of the data was shared with American officials at the National Security Agency, though the British ran queries of the data using a search tool provided by the N.S.A. called XKeyscore, according to a report on Thursday by The Guardian.