Activation Lock, a security feature that Apple first announced alongside iOS 7, is supposed to be a theft deterrent by making it harder for lost and stolen devices to be reactivated on the second hand market. The feature accomplishes this by linking a device’s activation to the user’s iCloud account. Since its launch Activation Lock has been credited by police as helping reduce iPhone theft in some cities, but there are some legitimate cases where users are unable to remove the Activation Lock.
For example, devices that are sold on the second hand market with Activation Lock enabled can only be disabled by following Apple’s steps to remove the feature using the original owner’s iCloud info. Apple’s advice is to make sure the feature is switched off before purchasing it, but that doesn’t do much for users with used iPhones in hand and no way to contact the original owner. Users that for whatever reason lose access to their Apple ID account could also be stuck with a legally purchased device they can’t unlock. Apple’s support doc notes “If you forget your password and cannot reset it, you will lose access to your Apple ID and may be unable to use or reactivate your device.”
The service claims it won’t remove the Activation Lock for devices that have been put in “Lost Mode”— a feature of Apple’s “Find My iPhone” app that Apple recommends enabling when a device is lost or stolen— but it’s unclear exactly how it might detect other stolen devices without the feature enabled.