ACCESSING CLASSIFIED FILES
Decrypting documents...
Your connection is being monitored
Back to Individuals
low risk
Mark Klein
AT&T Whistleblower, Former Technician
AT&T Communications Technician Who Exposed NSA Room 641A
Overview
Mark Klein is a former AT&T communications technician who in 2006 revealed that the NSA had installed surveillance equipment at AT&T's San Francisco switching facility in a secret room known as Room 641A. His disclosure provided the first concrete evidence of NSA domestic mass surveillance of internet traffic.
Key Affiliations
Controversies & Concerns
ROOM 641A: Revealed NSA had a secret room at AT&T San Francisco facility splitting fiber optic cables to copy internet traffic
EFF LAWSUIT: His evidence was central to Hepting v. AT&T, the EFF's landmark NSA surveillance lawsuit
DOMESTIC SURVEILLANCE PROOF: Provided first physical evidence that NSA was tapping domestic internet backbone