A published report say Britain's communications spy agency intercepted and stored screenshots from hundreds of thousands of webcams, and says the multi-year operation yielded a huge trove of intimate photographs of unsuspecting users.
The Guardian says GCHQ intercepted video chats of 1.8 million users in a six-month period of 2008, and that the program was still active in 2012. The report said the project, code-named "optic nerve," targeted video chats such as those offered by the Yahoo Messenger service.
The Guardian report is based on data leaked by former U.S. National Security Agency contractor Edward Snowden.
In a written statement Thursday, Yahoo said the report represents " a whole new level of violation of our users' privacy." The California-based company also said it was not aware of the snooping and would never condone it.
The newspaper said the spy agency refused to answer a series of questions about the reported program. It said the snooping was at least in part aimed at identifying targets using automatic facial recognition software.
The report also said the British agency eventually excluded images in which software had not detected any faces from search results, as part of an effort to prevent staff from viewing explicit images.
Previous disclosures from Snowden, who faces criminal charges in the United States and lives in exile in Russia, show the NSA was actively exploring the surveillance potential of video game consoles. NSA analysts also are thought to have infiltrated virtual games like "World of Warcraft" to spy on targets.