Federal law enforcement attempts to use cell phones as tracking devices were rebuked twice this month by lower court judges, who say the government cannot get real time tracking information on citizens without showing probable cause.

This summer, Department of Justice officials separately asked judges from Texas and Long Island, New York to sign off on orders to cellular phone service providers compelling them to turn over phone records and location information – in real time – on two different individuals.

Both judges rejected the location tracking portion of the request in harshly worded opinions, concluding investigators cannot turn cell phones into tracking devices by simply telling a judge the information is likely "relevant" to an investigation.

"When the government seeks to turn a mobile telephone into a means for contemporaneously tracking the movements of its user, the delicately balanced compromise that Congress has forged between effective law enforcement and individual privacy requires a showing of probable cause," wrote Magistrate Judge James Orenstein of New York in the latest decision Monday. (.pdf).

In the Long Island case, the DOJ asked to record the location of the cell towers that handled a call using information in a phone's "control channel," which is separate from the voice channel used in a mobile telephone call, which would give only a rough approximation of a user's locations and movement.

In the Texas case, the government sought to capture information regarding the strength, angle and timing of the caller's signal measured at two or more cell sites – data that might allow investigators to pinpoint a person's location using triangulation.

Orenstein handed down his 57-page opinion the same day as the Electronic Privacy Information Center released documents acquired in a Freedom of Information Act lawsuit, which showed the FBI had repeatedly violated its own rules about surveillance of American citizens.

The DOJ applied for the real time cell tracking information alongside orders to install so called "pen registers" and "trap and trace devices" which let investigators immediately learn the dialing information of incoming and outgoing calls.

These orders are relatively easy for the government to get since the Supreme Court ruled that there is no expectation of privacy in the phone numbers a person dials, and federal law requires judges to issue the orders so long as law enforcement promises the information will likely be relevant. The government cited another law, the Stored Communications Act, to argue those devices could be also used to capture the location-focused information.

Kevin Bankston, an attorney at the Electronic Frontier Foundation, which filed a friend of the court brief (.pdf) in the New York case, says the Justice Department may have been using cell phones to track people for a long time, since judges typically don't publish opinions on such orders.

"This is a true victory for privacy in the digital age, where nearly any mobile communications device you use might be converted into a tracking device," Bankston said in a statement. "Judges are starting to realize that when it comes to surveillance issues, the DOJ has been pulling the wool over their eyes for far too long."

Bankston noted in an interview that the Justice Department attempted to convince Orenstein he had the authority, under another federal law called the All Writs Act, to order the cell phone tracking by revealing that other judges had used that statute to authorize real time tracking of credit-card purchases, which the government referred to as a "Hotwatch Order."

It is unclear if those orders are limited to tracking fugitives or if they are also being used in ordinary criminal investigations.

Both judges concluded that Congress needed clarify the laws regarding cell phone tracking.

Though House and Senate lawmakers are currently battling over the final form of the reauthorization of the Patriot Act, it is unlikely the bill will clarify the cell phone tracking issue.

The Justice Department is expected to appeal both judges' decisions, but did not return a call for comment by press time.