Technology is making it easier to track and apprehend criminals in real time, but some civil libertarians worry that Fourth Amendment protections are being flouted in the process. Many new cell phones come equipped with tracking devices that can pinpoint the location of the phone to within 30 feet. The feature offers lots of possibilities both to users and law enforcement.

Some cell phone providers offer parents the option of setting up a virtual fence that notifies them when their child strays beyond a certain distance from home or another preset location. Other companies offer users the ability to be notified when friends are close by. And even the simplest phones now have enhanced 911 capability mandated by federal law, which can detect a caller's location within a broad area through triangulated radio signals sent to cell towers.

But does having a cell phone now place ordinary citizens at risk of Big Brother keeping tabs on them everywhere they go, violating the Fourth Amendment's guarantee against unreasonable searches? Apparently some judges think so.

In a highly unusual move, a federal judge in Texas not only refused to issue a warrant to the Drug Enforcement Administration that would have allowed access to tracking data on a suspected drug dealer's whereabouts, but decided to publish the opinion this week, as well. Now The Washington Post has taken up the cause, noting that several such requests have been turned down recently because the government does not have probable cause to gain access to the information.

The Fourth Amendment guarantees individuals have the right "to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures," and that "no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized." But of course, the Framers had no idea when they wrote those words that ordinary Americans would one day willingly carry around devices that could track their every movement and provide that information to scores of individuals.

Many people already have signed up to have private companies track their cars with GPS systems. Others are thrilled that their friends can find them at the local mall by carrying phones equipped with an alert system that notifies them when callers in their loop are nearby. Parents love the "chaperone" kid-tracking system offered by some cell companies, even if their kids don't. When it comes to cell phones and other electronic devices, privacy seems to be the last thing on most users' minds. Still it is the government's ability to tap into this system that has civil libertarians concerned.

Nonetheless, law enforcement's ability to zero in on a criminal's whereabouts no doubt saves lives. The Post acknowledges the government's tracking ability allowed federal agents to pinpoint the location of a serial murderer linked to at least six murders in four states. The killer died in a shootout in Florida in October 2006 while being pursued by police before he could kill again.

But what if a crime were in progress when the government sought the information? What if a child had been abducted and the police had reason to suspect that a convicted child molester had fled the area with the child? Would Fourth Amendment purists really want to argue that the government should not gain access to information that could help them locate the child before he is hurt?

One simple solution would be to require telecommunications companies to notify buyers that their phones include tracking devices, that this information may be accessed by law enforcement agencies and require subscribers to give their assent in order to purchase the cell phone service. Some judges have ruled already that law enforcement access to cell phone transmission data without a warrant is implicit because the government did not install the tracking devices and users voluntarily carry the devices and agree to permit the transmission of location data to the cell phone carrier. But a simple notice would make it clear that buyers should beware of using cell phones in criminal activity.

Of course, anyone who is really worried about Big Brother tracking him down can opt not to carry a cell phone at all.