Klein, a former AT&T technician turned whistleblower, exposed mass surveillance by the U.S. government in 2006.

Mark Klein, a whistleblower who exposed a National Security Agency program of mass government spying on American internet ...

In 2006, a retired AT&T engineer knocked on the door of the EFF's office in a rundown part of San Francisco's Mission ...

In 2006, he shared corporate documents showing how the National Security Agency was accessing internet data through a secret room in an AT&T office building.

Before Edward Snowden, Mark Klein blew the whistle on NSA internet spying. Best of CES 2025 Awards ➜ We may earn a commission ...

In 2006 the AT&T whistleblower exposed a secret room inside the company that routed network traffic to the NSA, leaking ...

The Electronic Frontier Foundation (EFF) recently announced the passing of Mark Klein, the AT&T whistleblower who exposed the ...

Mark Klein in the 2007 PBS Frontline episode "Spying on the Home Front" (left) and door revealed to be an NSA spying room at AT&T in the mid-2000s. Screnshots: PBS Mark Klein, the former AT&T ...

The US whistleblower Mark Klein is dead. He made it public for the first time that the NSA was also eavesdropping on US ...