Activation Lock is a security feature introduced in iOS 7. When a user enables "Find My iPhone/iPad," the device automatically locks to the Apple ID.
With Activation Lock on, no one (even after factory reset) can use the device without the original Apple ID. While this protects against theft, many used iPhone sellers forget to sign out of their Apple ID β leaving buyers with a "brick" device.
Before purchasing any used iPhone/iPad, always verify the Activation Lock is OFF.
