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.

Mark Klein, the former AT&T employee who helped expose the fact that the National Security Agency was spying on vast amounts of internet traffic in the U.S. during the mid-2000s, died in Oakland ...

Mark Klein, a Whistleblower Who Revealed Domestic Spying, Dies at 79. The AT&T technician predated Edward Snowden by seven years, but his allegations were never able to achieve traction. By .

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

Mark Klein, the AT&T technician who blew the whistle on one of the most extensive illegal surveillance operations in American history, has died. He was 79. He was an unlikely hero.

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.