WASHINGTON - November 17, 2008 - Federal law enforcement may be able to track cellular phone users' locations without the help of the telecommunications companies themselves, according to a report issued Sunday.

Documents obtained by the American Civil Liberties Union under a Freedom of Information Act request suggest that existing technology allows law enforcement to bypass wireless companies in locating individual cell phone users.

Using "triggerfish" technology, mobile phones are tricked into transmitting their serial numbers, phone numbers and other data by posing as a cellular phone tower. Until now, it's been believed that such technology could only be successfully employed with the help of the telecoms themselves, because the specific location of the phone couldn't be traced with enough accuracy.

But a document obtained by the ACLU and the Electronic Frontier Foundation from the U.S. Justice Department in a lawsuit and posted online last week, says triggerfish can be deployed "without the user knowing about it and without involving the cell phone provider."

The detail was noted by the ACLU's Rachel Myers on Daily Kos and highlighted in a posting on Ars Technica on Sunday.

As Ars Technica explains, "That may be significant because the legal rulings requiring law enforcement to meet a high "probable cause" standard before acquiring cell location records have, thus far, pertained to requests for information from providers, pursuant to statutes such as the Communications Assistance for Law Enforcement Act (CALEA) and the Stored Communications Act."