Most Americans carry cellphones, but many may not know that government agencies can track their movements through the signals emanating from the handset.
In recent years, law enforcement officials have turned to cellular technology as a tool for easily and secretly monitoring the movements of suspects as they occur. But this kind of surveillance - which investigators have been able to conduct with easily obtained court orders - has now come under tougher legal scrutiny.
In the last four months, three federal judges have denied prosecutors the right to get cellphone tracking information from wireless companies without first showing "probable cause" to believe that a crime has been or is being committed. That is the same standard applied to requests for search warrants.
The rulings, issued by magistrate judges in New York, Texas and Maryland, underscore the growing debate over privacy rights and government surveillance in the digital age.
With mobile phones becoming as prevalent as conventional phones (there are 195 million cellular subscribers in this country), wireless companies are starting to exploit the phones' tracking abilities. For example, companies are marketing services that turn phones into even more precise global positioning devices for driving or allowing parents to track the whereabouts of their children through the handsets.
Not surprisingly, law enforcement agencies want to exploit this technology, too - which means more courts are bound to wrestle with what legal standard applies when government agents ask to conduct such surveillance.
Cellular operators like Verizon Wireless and Cingular Wireless know, within about 300 yards, the location of their subscribers whenever a phone is turned on. Even if the phone is not in use it is communicating with cellphone tower sites, and the wireless provider keeps track of the phone's position as it travels. The operators have said that they turn over location information when presented with a court order to do so.
By the way, CBS's Websites for the CSI series shows have ready links under a tab marked "handbook" of "evidence," "tools," and "procedure" to explain what they are doing that is the easiest place to look when a crime lab person slips into "forensic babble." See the websites of CSI and CSI: NY where the two appear to be the same. For litigators who need to know, it is as good as any book.
[cross posted to www.FourthAmendment.com]
