The feature has been revealed on iOS 11.4.
A new feature called ‘USB Restricted Mode’ was just seen in the beta version of iOS 11.4 which is currently being tested by developers. This new mode will prevent access to any iOS device after seven days of not being unlocked.
This adds another layer of protection in the case that your smartphone is stolen, where it can be deemed potentially useless if they can’t get inside the device. Hooking it up to any computer through USB will only charge the device and access will be restricted.
This may be Apple’s countermeasure to programs like GrayKey, which can randomly guess the user password over and over until it gets the correct one – but for this to work GrayKey needs you smartphone plugged into your computer. If USB Restricted Mode is turned then there is a chance that the program is deemed unusable.
Privacy has been a major point of concern for Apple, even defying the request law enforcement to create a ‘backdoor’ for iOS devices so it can easily get access to potential evidence when it is an accessory to a crime.
Apple hasn’t commented on the new feature – but will most likely highlight it when WWDC 2018 happens next month.