cross-posted from: https://infosec.pub/post/24940344

EFF is deeply saddened to learn of the passing of Mark Klein, a bona fide hero who risked civil liability and criminal prosecution to help expose a massive spying program that violated the rights of millions of Americans. Mark didn’t set out to change the world. For 22 years, he was a telecommunications technician for AT&T, most of that in San Francisco. But he always had a strong sense of right and wrong and a commitment to privacy. Mark not only saw how it works, he had the documents to prove it. When the New York Times reported in late 2005 that the NSA was engaging in spying inside the U.S., Mark realized that he had witnessed how it was happening. He also realized that the President was not telling Americans the truth about the program. And, though newly retired, he knew that he had to do something. He showed up at EFF’s front door in early 2006 with a simple question: “Do you folks care about privacy?”  We did. And what Mark told us changed everything. Through his work, Mark had learned that the National Security Agency (NSA) had installed a secret, secure room at AT&T’s central office in San Francisco, called Room 641A. Mark was assigned to connect circuits carrying Internet data to optical “splitters” that sat just outside of the secret NSA room but were hardwired into it. Those splitters—as well as similar ones in cities around the U.S.—made a copy of all data going through those circuits and delivered it into the secret room.

Mark[…]