Find My iPhone has a feature called Activation Lock which matches up with what you're describing: https://support.apple.com/en-us/HT201365 https://support.apple

Find My iPhone has a feature called Activation Lock which matches up with what you're describing: https://support.apple.com/en-us/HT201365 https://support.apple.com/en-us/HT201365 The phone won't do anything until the person who turned on the lock turns it off again.