Seven years before Edward Snowden revealed mass surveillance programs run by the National Security Agency, a retired AT&T technician named Mark Klein attempted to sound the alarm on domestic ...

I n October 2003, the AT&T technician Mark Klein was transferred to a small office on San Francisco’s Folsom Street where he was tasked with maintaining the seventh floor “internet room ...

Mark Klein, a whistleblower who exposed a National Security Agency program of mass government spying on American internet traffic in the 2000s, has died. He was 79 years old.

The Electronic Frontier Foundation (EFF) recently announced the passing of Mark Klein, the AT&T whistleblower who exposed the NSA's mass surveillance program nearly two decades ago. Klein worked ...

That person was Mark Klein, who died on March 8 this year from cancer. He was 79. After a life working in telecoms, Klein ...

Klein's home office is lined with awards and newspaper clippings dating back to the day he decided to take pictures of a room known only as 641-A. "One of the doors, which I took a picture of, has ...

Retired AT&T technician Mark Klein in 2013, at his home in Alameda, California. He revealed how the NSA was accessing vast amounts of internet data through a secret room in San Francisco.