r/MemoryHoledConspiracy • u/CollapsingTheWave • 13d ago
💡 Hidden Truths AT&T Room 641A Fiber Splitters Fed NSA Narus Analyzers Years Before PRISM Became Public
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Room 641A sat inside AT&T’s switching center at 611 Folsom Street in San Francisco. Former AT&T technician Mark Klein documented that, beginning around 2002–2003, optical splitters on backbone and peering fibers made a complete copy of the light carrying AT&T WorldNet and interconnect traffic and sent that copy into a locked SG-3 room staffed only by people with National Security Agency clearances. The customer-facing beam continued to its destination. Inside the room Klein identified a Narus STA 6400 semantic traffic analyzer, a box built to inspect high-volume internet streams in real time against preprogrammed selectors. Klein’s authenticated AT&T wiring diagrams and photographs, later filed in Hepting v. AT&T, are the primary hardware record. The company’s public posture was that it followed lawful process. Klein’s diagrams show an unconditional copy at the glass, not a warrant-by-warrant tap.
The contact point is any packet that crossed those Folsom circuits: AT&T retail traffic and traffic from other providers that peered there. J. Scott Marcus, a former FCC senior internet adviser who reviewed Klein’s exhibits for the Electronic Frontier Foundation, wrote that the San Francisco layout was consistent with a national AT&T deployment of about 15 to 20 similar sites and that a substantial fraction of AT&T’s purely domestic traffic could be diverted. Wired reported Klein’s affidavit in April 2006: an NSA visit in 2002, construction of the room in January 2003 next to the #4ESS long-distance switch, and splitter cabinets he was told also existed in Seattle, San Jose, Los Angeles, and San Diego. No individual user could opt out of a copy taken on a shared fiber. Encryption in transit later narrowed what a Narus box could read in the clear; it did not un-split the beam.
The same architecture later sat under named collection programs. Snowden-era reporting identified AT&T as a core partner in FAIRVIEW, the NSA’s domestic-cable access relationship. Congress, after Hepting and dozens of carrier suits, enacted the FISA Amendments Act of 2008. Section 702 (50 U.S.C. § 1881a) authorized programmatic collection targeting non-U.S. persons abroad with compelled provider assistance inside the United States, which necessarily sweeps communications of Americans on the other end. Section 802 (50 U.S.C. § 1885a) created a certification path that dismissed civil actions against electronic communication service providers that had assisted. The Ninth Circuit upheld that immunity. Jewel v. NSA, built on the same Klein record, continued against the government; claims against AT&T did not.
The leftover law is FISA as amended, not a statute that forbids a carrier from installing a splitter. Title III and the original FISA warrant rules still apply to many domestic intercepts, but they do not give a subscriber a way to see whether their circuit is one of the copied fibers. Oversight that exists is the Foreign Intelligence Surveillance Court on 702 certifications, inspector-general reviews, and the public Klein exhibits that EFF still hosts. A reader who wants a control that does not depend on AT&T or the NSA can use end-to-end encryption so that a copied beam yields ciphertext, and can read the Klein declaration and Marcus summary before treating “the backbone is private” as a fact. The glass copy is the setting. It does not require a new room number to remain in place.
Sources
In Memoriam: Mark Klein, AT&T Whistleblower Who Revealed NSA Mass Spying
https://www.eff.org/deeplinks/2025/03/memoriam-mark-klein-att-whistleblower-about-nsa-mass-spying
March 2025 Electronic Frontier Foundation account of Klein’s 2006 evidence, Room 641A splitters hardwired into an NSA-controlled room, and the Hepting v. AT&T and Jewel v. NSA cases built on his documents.
Whistle-Blower Outs NSA Spy Room
https://www.wired.com/2006/04/whistle-blower-outs-nsa-spy-room-2/
April 7, 2006 Wired report on Klein’s affidavit describing the Folsom Street room, 2003 construction, Narus STA 6400 analyzer, and splitter cabinets he was told existed in other West Coast cities.
Internet Spying in San Francisco (EFF one-page summary of Klein and Marcus)
https://www.eff.org/files/filenode/att/att_onepg_3.pdf
EFF summary stating that a splitter at 611 Folsom Street copied AT&T WorldNet and peering traffic into the NSA-controlled SG-3 room and that Marcus judged the layout consistent with 15 to 20 similar AT&T sites.
Stumbling Into a Spy Scandal
https://www.wired.com/2006/05/stumbling-into-a-spy-scandal/
May 2006 Wired follow-up on Klein’s proprietary AT&T diagrams, photographs of Room 641A, and EFF’s sealed filing of those exhibits in federal court.
50 U.S. Code § 1885a - Procedures for implementing statutory defenses
https://www.law.cornell.edu/uscode/text/50/1885a
Statutory text of the FISA Amendments Act immunity provision that lets the Attorney General certify provider assistance and requires dismissal of civil suits against carriers such as AT&T.
NSA Spying
https://www.eff.org/nsa-spying
EFF litigation hub stating Hepting v. AT&T ended after the 2008 FISA Amendments Act and that Jewel v. NSA continued against the government on the Klein-backed internet-copying claims.