Is the NSA spying on U.S. Internet traffic?

Since last December, news reports have asserted that the NSA has conducted warrantless spying on the phone and e-mail communications of thousands of people inside the U.S., and has been secretly collecting the phone call records of millions of Americans, using data provided by major telecommunications companies, including AT&T. Such operations would represent a fundamental shift in the NSA's secretive mission, which over the last three decades is widely understood to have focused exclusively on collecting signals intelligence from abroad.

The reported operations have sparked fierce protest by lawmakers and civil liberties advocates, and have raised fundamental questions about the legality of Bush administration policies, including their consequences for the privacy rights of Americans. The Bush administration has acknowledged the use of domestic surveillance operations since Sept. 11, 2001, but maintains they are conducted within the legal authority of the presidency. Several cases challenging the legality of the alleged spying operations are now pending in federal court, including suits against the federal government, and AT&T, among other telecom companies.

In a statement provided to Salon, AT&T spokesman Walt Sharp said: "If and when AT&T is asked by government agencies for help, we do so strictly within the law and under the most stringent conditions. Beyond that, we can't comment on matters of national security."

According to the two former AT&T workers and the Klein documents, the room in the pivotal Bridgeton facility was set up several months before the room in San Francisco. According to the Klein documents, the work order for the San Francisco room came from Bridgeton, suggesting that Bridgeton has a more integral role in operations using the secured rooms.

The company's Bridgeton network operations center, where approximately 100 people work, is located inside a one-story brick building with a small two-story addition connected to it. The building shares a parking lot with a commercial business and is near an interstate highway.

According to the two former workers, the secret room is an internal structure measuring roughly 20 feet by 40 feet, and was previously used by employees of the company's WorldNet division. In spring 2002, they said, the company moved WorldNet employees to a different part of the building and sealed up the room, plastering over the window openings and installing steel double doors with no handles for moving equipment in and out of the room. The company then installed the high-tech mantrap, which has opaque Plexiglas-like doors that prevent anyone outside the room from seeing clearly into the mantrap chamber, or the room beyond it. Both former workers say the mantrap drew attention from employees for being so high-tech.

Telecom companies commonly use mantraps to secure data storage facilities, but they are typically less sophisticated, requiring only a swipe card to pass through. The high-tech mantrap in Bridgeton seems unusual because it is located in an otherwise low-key, small office building. Tice said it indicates "something going on that's very important, because you're talking about an awful lot of money" to pay for such security measures.

The vetting process for AT&T workers granted access to the room also points to the NSA, according to Tice and Aid.

The former network technician said he knows at least three AT&T employees who have been working in the room since 2002. "It took them six months to get the top-security clearance for the guys," the network technician said. "Although they work for AT&T, they're actually doing a job for the government." He said that each of them underwent extensive background checks before starting their jobs in the room. The vetting process included multiple polygraph tests, employment history reviews, and interviews with neighbors and school instructors, going as far back as elementary school.

Aid said that type of vetting is precisely the kind NSA personnel who receive top-secret SCI (Sensitive Compartmented Information) clearance go through. "Everybody who works at NSA has an SCI clearance," said Aid.

It's possible the Bridgeton room is being used for a federal law enforcement operation. According to the Communications Assistance for Law Enforcement Act of 1994, telecom companies are required to assist law enforcement officials who have legal authorization to conduct electronic surveillance, either in pursuit of criminal suspects or for the protection of national security. The companies must design or modify their systems to make such surveillance possible, essentially by making them wiretap-ready.

The FBI is the primary federal agency that tracks and apprehends terrorist suspects within the U.S. Yet, there are several indications that the Bridgeton room does not involve the FBI.

"The FBI, which is probably the least technical agency in the U.S. government, doesn't use mantraps," Aid said. "But virtually every area of the NSA's buildings that contain sensitive operations require you to go through a mantrap with retinal and fingerprint scanners. All of the sensitive offices in NSA buildings have them." The description of the opaque Plexiglas-like doors in Bridgeton, Aid said, indicates that the doors are likely infused with Kevlar for bulletproofing -- another signature measure that he said is used to secure NSA facilities: "You could be inside and you can't kick your way out. You can't shoot your way out. Even if you put plastique explosives, all you could do is blow a very small hole in that opaque glass."

Next page: Could the Bridgeton room be used for a government data mining operation?