Apple's Find My iPhone service can prove handy should you leave your iPhone in a taxi and various cases have been reported of people being reunited with stolen iPhones after tracking the devices whereabouts using Apple's free Find My iPhone service.

Apple isn't the only company that offers customers the ability to locate a lost phone, however. Various mobile phone networks and other manufacturers also offer services that help customers pinpoint the location of a lost or stolen phone (or the whereabouts of a person with that phone).

Being able to locate a lost phone is undeniably useful, but these tools aren't as reliable as many suspect.

In addition, concern has been raised about the number of victims of mobile phone theft that have taken it upon themselves to approach suspected thieves, vigilante style.

In one case the owner of an iPhone lost on 30 December 2012 used Find My iPhone to locate his device and then went to confront the thief; a YouTube video shows the fight between the vigilante and the iPhone robber.

Not every story has a happy ending. As we reported last year, one man was accused of 'trespass via radio wave' when he tried to recover his stolen iPhone.

Read next: How to turn off Find My iPhone

Wrongly accused of phone theft

In the latest proof that people should be wary of attempting to locate their lost phones using these tracking services, it has emerged that a problem with the GPS location-tracking services on Sprint phones is mistakenly leading dozens of people to the home of an innocent 59-year-old retiree in North Las Vegas.

According to the Las Vegas Review-Journal, the problem started in 2011, when an angry couple woke Wayne Dobson up in the middle of the night, because Sprint's app had led them straight to his house.

"It's very difficult to say, 'I don't have your phone,' in any other way other than, 'I don't have your phone,' " Dobson said.

So many angry people have turned up at his house at all hours of the day and night, demanding that he return them their lost phones, some showing him evidence on tablets and calling the police, that Dobson now sleeps near his front door on weekends so that he can answer the door quickly, and he has had to post a sign on the front of his house.

“It’s a hell of a problem,” he said. “It would be nice to be able to get a good night’s sleep.”

Once, dispatchers responding to a 911 domestic dispute call were unable to locate a woman in an escalating argument. They used GPS to locate the phone, and sent police officers to Dobson’s house.

"I screamed at him, 'Who are you? Get out of my yard!' " Dobson said. "And he said, 'We're the police, open the door.' "

Sprint has been contacted about the problem and say that they are working on it, but have yet to determine the cause.

To find out how to protect your iPhone from theft, read our feature here.


Man poses as woman on dating site to lure iPhone thief, another films violent confrontation, posts it online

Man who used Find My iPhone accused of 'trespass via radio wave' 

How to protect your iPhone from theft