Federal officials are routinely asking courts to order cellphone companies to furnish real-time tracking data so they can pinpoint the whereabouts of drug traffickers, fugitives and other criminal suspects, according to judges and industry lawyers. In some cases, judges have granted the requests without requiring the government to demonstrate that there is probable cause to believe that a crime is taking place or that the inquiry will yield evidence of a crime. Privacy advocates fear such a practice may expose average Americans to a new level of government scrutiny of their daily lives. The requests and orders are sealed at the government's request, so it is difficult to know how often the orders are issued or denied. Most people don't realize it, but they're carrying a tracking device in their pocket," said Kevin Bankston of the privacy advocacy group Electronic Frontier Foundation. "Cellphones can reveal very precise information about your location, and yet legal protections are very much up in the air." In a stinging opinion this month, a federal judge in Texas denied a request by a Drug Enforcement Administration agent for data that would identify a drug trafficker's phone location by using the carrier's E911 tracking capability. E911 tracking systems read signals sent to satellites from a phone's Global Positioning System (GPS) chip or triangulated radio signals sent from phones to cell towers. "Law enforcement routinely now requests carriers to continuously 'ping' wireless devices of suspects to locate them when a call is not being made . . . so law enforcement can triangulate the precise location of a device and [seek] the location of all associates communicating with a target," wrote Christopher Guttman-McCabe, vice president of regulatory affairs for CTIA -- the Wireless Association.