Mark Klein was a veteran AT&T
technician in 2002 when he began to see what he thought
were suspicious connections between that telecommunications
giant and the National Security Agency.
But he kept quiet about it until news
broke late last year that President Bush had approved
an N.S.A. program to eavesdrop without court warrants
on Americans suspected of ties to Al Qaeda.
Now Mr. Klein and a few company documents
he saved have emerged as key elements in a class-action
lawsuit filed against AT&T on Jan. 31 by a civil
liberties group, the Electronic Frontier Foundation.
The suit accuses the company of helping the security
agency invade its customers' privacy.
Mr. Klein's account and the documents
provide new details about how the agency works with
the private sector in intercepting communications
for intelligence purposes.
The documents, some of which Mr. Klein
had earlier provided to reporters, describe a mysterious
room at the AT&T Internet and telephone hub in
San Francisco where he worked.
The documents, which were examined
by four independent telecommunications and computer
security experts at the request of The New York Times,
describe equipment capable of monitoring a large quantity
of e-mail messages, Internet phone calls, and other
The equipment, which Mr. Klein said
was installed by AT&T in 2003, was able to select
messages that could be identified by keywords, Internet
or e-mail addresses or country of origin and divert
copies to another location for further analysis.
The security agency began eavesdropping
without warrants on international phone calls and
e-mail messages of people inside the United States
suspected of terrorist links soon after the Sept.
After disclosing the program last
December, The New York Times also reported that the
agency had gathered data from phone and e-mail traffic
with the cooperation of several major telecommunications
The technical experts all said that
the documents showed that AT&T had an agreement
with the federal government to systematically gather
information flowing on the Internet through the company's
The gathering of such information,
known as data mining, involves the use of sophisticated
computer programs to detect patterns or glean useful
intelligence from masses of information.
''This took expert planning and hundreds
of millions of dollars to build,'' said Brian Reid,
director of engineering at the Internet Systems Consortium
in Redwood City, Calif. ''This is the correct way
to do high volume Internet snooping.''
Another expert, who had designed large
federal and commercial data networks, said that the
documents were consistent with administration assertions
that the N.S.A. monitored only foreign communications
and communications between foreign and United States
locations, partly because of the location of the monitoring
sites. The network designer was granted anonymity
because he believed that commenting on the operation
could affect his ability to work as a consultant.
The documents referred to a second
location, in Atlanta, and suggested similar rooms
might exist at other AT&T switching sites.
Mr. Klein said other AT&T technicians
had told him of such installations in San Jose, Calif.;
Los Angeles; San Diego; and Seattle.
The Internet hubs there carry a significant
amount of international traffic. The network designer
and other experts said it would be a simple technical
matter to reprogram the equipment to intercept purely
domestic Internet traffic.
The Department of Justice initially
asked the Electronic Frontier Foundation not to file
Mr. Klein's documents in court, but a review determined
that they were not classified and the government dropped
its objection. The foundation filed the documents
under seal because of concern about releasing proprietary
On Monday, AT&T filed a motion
with a federal judge in San Francisco asking the court
to order the foundation to return the documents because
they were proprietary.
The documents showed that the room
in San Francisco, which Mr. Klein says was off-limits
to most employees but serviced by a company technician
working with the security agency, contained computerized
equipment that could sift through immense volumes
of traffic as it passed through the cables of AT&T's
WorldNet Internet service.
According to the documents, e-mail
messages and other data carried by 16 other commercial
Internet providers reached AT&T customers through
the San Francisco hub.
One piece of filtering equipment described
in the documents was manufactured by Narus, based
in Mountain View, Calif.
The equipment could be programmed
to identify and intercept voice or data conversations
between e-mail, telephone or Internet addresses, said
Steve Bannerman, the company's vice president for
Buyers included companies trying to
comply with the Communications Assistance for Law
Enforcement Act of 1994, which requires that communications
systems have a wiretapping capability built in.
Typically, law enforcement interceptions
are done on a case by case basis and require warrants.
Mr. Bannerman said he could not comment
further because Narus had not announced any sales
to the federal government. William P. Crowell, a former
deputy director of the N.S.A, is on the Narus board.
In an interview, Mr. Klein said he
did not have a security clearance but had witnessed
interactions between colleagues who did have clearances
and the highly secretive N.S.A. ''It was strange and
sort of suspicious,'' he said.
Mr. Klein said he learned of an agency
connection to the mysterious room in 2002 when a company
manager told him to expect a visit from an N.S.A.
official who wanted to speak with another senior company
technician about ''a special job.'' That technician
later installed the equipment in the room, he said.
Based on his observations and technical
knowledge, Mr. Klein concluded that the equipment
permitted ''vacuum-cleaner surveillance'' of Internet
traffic. Mr. Klein, 60, who retired in 2004 after
23 years with AT&T and lives near Oakland, Calif.,
said he decided to make his observations known because
he believed the government's monitoring was violating
Americans' civil liberties.
An AT&T spokesman at the company's
corporate headquarters in San Antonio declined to
comment on Mr. Klein's statements.
''AT&T does follow all laws with
respect to assistance offered to government agencies,''
said Walt Sharp, the AT&T spokesman. ''However,
we are not in a position to comment on matters of
Asked to comment, Don Weber, a spokesman
for the N.S.A., said, ''It would be irresponsible
of us to discuss actual or alleged operational issues
as it would give those wishing to do harm to the United
States the ability to adjust and potentially inflict
Copyright 2006 The
New York Times Company