https://thenextweb.com/apple/2018/07/10/ios-11-4-1-can-prevent-cops-from-cracking-your-iphone-but-theres-a-catch/

The latest update to iOS brings a new feature called USB Restricted Mode that can prevent unauthorized access to the contents of your iPhone through the use of cracking devices that connect via the Lightning port.

The feature, which you’ll find in iOS 11.4.1, locks down the data connection over the Lightning port one hour after the last time your iOS device is unlocked. That means if that someone plugs in a device like the GrayKey, favored by police forces in the US, they won’t be able to break the passcode protection and access the data on your phone.