Cell Phone Flaw Puts Homeowners at Risk

Nationwide Problem Bedevils Affected Homeowners, Police

Strangers and police showing up at all hours on your doorstep unannounced, banging on your front door, demanding to be let in and sometimes brandishing a gun: That's the nightmare being faced now by homeowners in at least three states, thanks to a flaw in the technology used to locate cell phones. It falsely gives these homeowners' addresses as places where lost or stolen phones can be found.

We wrote earlier this week about Wayne Dobson of Nevada. In the last two years he has lived in his North Las Vegas home, five people--all missing their Sprint cell phones--have come knocking on his door, demanding that he return their handsets.

If a GPS tracker for your lost cell phone leads you to Dobson's home, you'll find a sign that reads, "No lost cell phones!! This location gives a false 'phone locator' position due to a cell tower behind this home. Please contact the North Las Vegas Police and file a report."

On Dec. 18, four men who Dobson described as "young" pounded on his door at around 2:30 a.m., shouting for him to return their phone. One of the men had a tablet with a tracking application, pointing to Dobson's home.

"I understand why people are upset. These are $300 or $500 devices," Dobson said. "I'm worrying about someone showing up in an agitated state, are drinking, and if that one person has a weapon perhaps. This is Las Vegas."

But apparently, Dobson's plight is not unique.

Our ABC News story elicited a response from Greg and Kelly Miles of Edgewater, Fla. They say they have been getting the same kind of scary visits for the past year and a half.

ABC's story, says Greg, sent "chills down our spine."

"The cops have showed up at my door in the middle of the night with assault rifles. We have also had angry people coming to our house and are very scared that someone might show up and do something really bad. Please help us if you can," Greg wrote in an email to ABC.

Greg and Kelly say their problem began in 2011, when an individual came to their house and accused them of having stolen his cell phone. He had tracked it, he said, to their home. "We didn't know what to think," Greg tells ABC. "We didn't have anyone's cell phone."

Since then three other seekers have come looking for their phones. "Some have come back multiple times."

On other occasions, Greg says, police have come in the middle of the night. "My wife looked out, and there were officers with assault rifles at the door. They said they'd received a 911 call from this house reporting an attempted suicide. The name they gave meant nothing to me."

Three weeks after that incident, a police officer pounded on the door at night. He said a stolen cell phone had been tracked to the home. Miles says he was interrogated, even after the officer had satisfied himself Miles was not harboring a stolen phone. "He asked me where I'd been all day."

Now Greg and his wife keep their door locked all the times. They are being harassed, he says, and they are afraid. "Maybe there are others like us," he speculates.

In New Orleans, WDSU News reports that an Algiers woman, Diana Pierre-Louis, has suffered similar visits. "It's humiliating," she is quoted as saying. "It is an attack on our dignity."

Miles says he is at a loss to explain the problem with which he, Dobson and Pierr-Louis are having to contend. Experts in phone-location technology, however, face no such confusion. They tell ABC News they think they have a very good idea of what's going on.

Ben Levitan, an expert on cell phone technology who holds 27 patents in the field, thinks the problem is arising, at least in Dobson's case, because of the way the cell phone location system works: If it tries and fails to get the exact location of the phone being sought (all cell phones being sold today, he says, contain GPS location-tracking technology) the system automatically resorts to finding the address of the cellular transmission tower nearest to the phone—for example, the cell phone tower near Dobson's home.

Levitan speculates that the address for the tower may have been entered incorrectly in the system: When a searcher seeks a missing phone, what he gets is the address for Dobson's home, not the tower.

A spokesperson for Sprint, the service provider for some of the people who have come to Dobson's house looking for their phones, offers a different but not contradictory explanation.

Stephanie Vinge Walsh of Sprint corporate communications says the problem arises from the fact that Dobson's house "happens to be in the center of a geometric circle denoting the coverage area." The address of that center is the address provided searchers "when a more precise location of a device is not readily available."

Whatever the explanation, it's all the same to Dobson when cops--or drunks--come pounding on his door at 3 a.m. "We sincerely regret the inconvenience experienced by Mr. Dobson," says Walsh.