Another Use of Wiretapping to Catch a Terrorist
By Larry Johnson on December 21, 2005 at 5:10 PM in Current Affairs
by
Larry C Johnson
An old friend, Paul Kaihla, who writes for Business 2.0, reminded me he had published a piece 4 years ago that highlighted one of the challenges of tracking terrorist targets. While this example falls outside the current debate about phone intercepts inside the United States, the technological challenge is the same. The fundamental point is that the law enforcement and intelligence community can deal with the threat. If they need new authorities they should seek them. But ignoring laws is not a prerogative of the President or any leader for that matter.
Weapons of the Secret War
By Paul Kaihla, November 01, 2001. . . The Escobar takedown shows how U.S. sigint can work with local forces to eliminate bad guys. In 1993 the CIA and a covert U.S. Army unit called Centra Spike spent months in Colombia monitoring Escobar’s communications from both the ground and the air, finally pinpointing his location when he made a call from his cell phone. Colombian special forces commandos gunned down the Medellmn cartel leader as he ran barefoot across the rooftop of an apartment building.
Sigint’s work against the cocaine cartels evolved into a game of high-tech cat-and-mouse, especially after Escobar’s death taught traffickers the vulnerability of cell phones. One of the cartels’ countermeasures is to “roll” cell phones to confuse wiretappers. Using scanners, they steal the identities of innocent bystanders’ mobile phones and program the “cloned” numbers into their own handsets for a few days at a time. Authorities can’t keep track of what phone numbers they should be tapping.
In response, authorities deployed a remarkable surveillance technology that operates over Colombia from spy planes. It uses a series of devices called IF-to-tape converters (“IF” stands for “intermediate frequency”), in conjunction with directional antennas, receivers, and wide-band recorders, to scoop up the major bands across the entire cellular spectrum. Loaded with the proper gear, one aircraft can record all of the cell traffic in a major city by circling it at a high altitude and exploiting the powerful microwave signals that form a handshake between cell sites in wireless networks. Back at the plane’s base, a computer extracts audio files of actual conversations from the captured signals. The audio files are then filtered with sophisticated voice recognition software, allowing intelligence analysts to identify all of a suspect’s conversations by his voice, no matter how many times he rolls his phones.
by Ronald Scott
* More novels by 
* 
(
)
- You'll have access to 18 million movies, TV shows, songs, magazines, and books, as well as ultra-fast Web browsing with Amazon Silk -- faster than iPad. Full e-mail and document access and a keyboard. Fire can transmit what is on your screen onto a connected TV or monitor without an accessory. It runs Flash (iPad doesn't). 
