New York Times:

In San Diego, a construction worker who said his iPhone had been stolen at a reggae concert chased the pilferer and wound up in a fistfight on the beach that a police officer had to break up. A New Jersey man ended up in custody himself after he used GPS technology to track his lost iPhone and attacked the wrong man, mistaking him for the thief.

Even an off-duty Los Angeles police detective pursued his son’s phone, which had been stolen at a soccer game. The officer, who asked that his name not be used for fear that civilians would follow his example, and his son used GPS to track the phone leaving the field.

They got in the car and followed it — first to a mall, then to a nearby home. The officer knocked on the door, and then his son called the phone, which went off inside the bag of the boy who had taken it from the field.

The officer urged anyone whose phone is stolen to call the police, noting that he had had three other off-duty officers with him.

Interesting read and solid advice. If someone steals your phone, call the police.