In the case of legal demands to review or access data stored on a phone or computer, if they are protected with a traditional password they are protected under the Fifth Amendment. If the device is protected with a fingerprint or facial detection as its password the government has used warrants to compel people to unlock their biometrically locked devices.
While fingerprint recognition can be bypassed or can be unlocked by others it is estimated by Apple to be 1 in 50,000 people. Face ID from Apple raises the protection to be 1 in 1 million. So there are positives in the new methods of protecting your device, but in legal circumstances only a traditional password is protected by any degree.
Depending on the information you have on your devices and your line of work this information is important to know about how to protect your information, or information of your clients and customers. Apple does provide a way to turn of facial recognition (Face ID) by pressing the power button five times in quick succession.
Article from Popular Science – https://www.popsci.com/iphonex-facial-recognition-legal-unlock