Mark Klein, a former AT&T technician turned whistleblower who uncovered mass surveillance by the U.S. authorities, has died at age 79.

Klein went public in 2006 with paperwork revealing that the NSA was utilizing a secret room in an AT&T hub in San Francisco to faucet into the spine of the web.

Behind the door of the now-infamous Room 641A, optical splitting wiretaps had been creating an an identical copy of uncooked web site visitors and funneling it again to the NSA. 

Klein’s disclosure was affirmation that the U.S. authorities was accessing the web knowledge on tens of millions of People utilizing powers granted by Congress within the aftermath of the September 11, 2001 terrorist assaults.

In 2013, then-NSA contractor Edward Snowden leaked hundreds of labeled paperwork to journalists detailing widescale NSA surveillance all over the world.

Klein’s demise was confirmed by the Electronic Frontier Foundation, the San Francisco-based digital rights group who Klein turned to, and which went on to sue the federal authorities following Klein’s disclosures. The case was finally dismissed.