USA Today: Pre-9/11 records help flag suspicious calling

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http://www.usatoday.com/news/washington/2006-05-22-nsa-template_x.htm

Pre-9/11 records help flag suspicious calling

WASHINGTON — Armed with details of billions of telephone calls, the National Security Agency used phone records linked to the Sept. 11, 2001 attacks to create a template of how phone activity among terrorists looks, say current and former intelligence officials who were briefed about the program.

The template, the officials say, was created from a secret database of phone call records collected by the spy agency. It has been used since 9/11 to identify calling patterns that indicate possible terrorist activity. Among the patterns examined: flurries of calls to U.S. numbers placed immediately after the domestic caller received a call from Pakistan or Afghanistan, the sources say.


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The officials, two current U.S. intelligence officials familiar with the program and two former U.S. intelligence officials, agreed to talk on condition of anonymity. The White House and the NSA refused to discuss the template or the program.

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Calls coming into the country from Pakistan, Afghanistan or the Middle East, for example, are flagged by NSA computers if they are followed by a flood of calls from the number that received the call to other U.S. numbers.