(CNN) - Another revelation in leaked documents from former NSA contractor Edward Snowden indicated intelligence services snagged images from webcams of more than 1 million Yahoo users.
According to a Thursday report by The Guardian, the NSA and British intelligence worked in tandem to grab still images of people, many of whom were not suspected of any wrongdoing.
"The structure of these programs is such that they collect lots of data in bulk," said Spencer Ackerman, a reporter for Guardian. "The idea is that on the front end you just collect a lot and worry about what you need later."
Within the program, dubbed Operation Optic Nerve, the British agency GCHQ reportedly collected webcam images from anonymous users from 2008 to 2010, saving one screen grab every five minutes.
One document stated a large quantity of the images were sexually explicit, showing "undesirable nudity." The program reportedly used facial recognition technology to help GCHQ track targets who were known Yahoo users.
"There's a great potential that American citizens' webcam data has been intercepted under this program because GCHQ, the British intelligence service, does not preselect out the images before it collects them," Ackerman said.
The NSA stated it does not ask foreign partners to grab intelligence it could not legally collect itself. A Yahoo representative said the company was unaware of the alleged operation.
"This report, if true, represents a whole new level of violation of users' privacy that is completely unacceptable," Yahoo stated.
GCHQ said it would not comment on intelligence matters but declared it acts within the law.
Copyright 2014 CNN. Getty Images, Yahoo and Guardian contributed to the report.