Apple added an Activation Lock feature to iOS in late 2013. Since that time, theft of the phones have dropped significantly.
The number of stolen iPhones dropped by 40 percent in San Francisco and 25 percent in New York in the 12 months after Apple Inc added a kill switch to its devices in September 2013. In London, smartphone theft dropped by half, according to an announcement by officials in the three cities.
When Activation Lock is enabled on an iOS device, you must first enter the device's Apple ID and password to erase and reactive it, or to turn off the GPS tracking.
If you have an iOS device, you can check your Activation Lock Status here.
