They have a plan, they have a pattern . . .

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.

What about analysts drowning in a sea of bad data?

The current and former intelligence officials say … The database enables intelligence analysts to focus on a manageable number of suspicious calling patterns. . .

About the Author

Michael Tanji

Michael Tanji spent nearly 20 years in the US intelligence community. Trained in both SIGINT and HUMINT disciplines he has worked at the Defense Intelligence Agency, the National Security Agency, and the National Reconnaissance Office. At various points in his career he served as an expert in information warfare, computer network operations, computer forensics, and indications and warning. A veteran of the US Army, Michael has served in both strategic and tactical assignments in the Pacific Theater, the Balkans, and the Middle East.