Mark Klein was working at AT&T‘s Geary Street switching facility in downtown San Francisco in 2002 when he received an email saying that someone from the NSA was coming to the office to do business. (..)

„As soon as I saw the splitter,“ Klein said, „I knew this was completely unconstitutional and illegal because they were copying everything. I‘m a technician, I know what this equipment does, and I traced the cable. This cable goes to that room, which we can‘t go into; that‘s a government room. And I knew what was on that cable…It was everything that went across the Internet then, which was Web browsing and email, and VoIP calls…Based on my understanding of the connections and equipement at issue…it appears the NSA is capable of conducting what amounts to vacuum-cleaner surveillance of all the data crossing the Internet…The physical apparatus gives them everything.“

The „physical apparatus“ Klein describes was a Narus system.