Keep your face, finger from unlocking your smartphone
Having to type in a passcode to unlock your smartphone is worse than having the device recognize your face or fingerprint – with one exception.
That’s if somebody with a badge directs you to unlock your device with one of those biometric identifiers. Courts have held that while law enforcement officials can’t force you to enter a passcode, they can demand that you show your face or touch a fingertip.
In one recent case, a Federal Bureau of Investigation agent unlocked an iPhone X by holding it up to the suspect’s face and asking him to look at it – revealing evidence of child pornography on the phone.
That case looks like a criminal getting what he deserved. But it doesn’t mean you should make things easier for somebody demanding to peek at your phone’s contents for no apparent reason – for instance, if you’re at a security checkpoint.
Fortunately, both Apple and Google offer shortcuts to disable their biometric-unlock features. Unfortunately, only one of them is widely available.
In Apple’s iOS 11 and 12, you can temporarily block its Touch ID fingerprint recognition or Face ID facial recognition with one of two sequences of button presses that launch an iPhone’s Emergency SOS mode.
On an iPhone 8 or a more recent model, press and hold the power/sleep button and either of the volume buttons. On an older iPhone, quickly press the power/sleep button five times in a row.
The phone’s screen will then show the Emergency SOS screen, making it obvious that you’ve locked out touch or face recognition; a swipe of the SOS slider will then call 911.
The latest version of Google’s Android, Android Pie, offers a more subtle way to cancel a phone’s biometric login, “lockdown mode.” But this option also suffers from two serious impediments.
The smaller one is that it’s inert by default. To enable lockdown, open the Settings app, tap “Security & location,” and then tap “Lock screen preferences” and finally “Show lockdown option.”
From then on, you only have to press the power/sleep button once, then hold it down again for about a second to display a vertical menu on the lock screen, with “Lockdown” third from the top. Tap that, and your fingerprint’s no good – plus, the phone will no longer show any notifications on the lock screen or unlock itself near designated Bluetooth devices.
The bigger problem with Lockdown: You almost certainly can’t use it yet. Android Pie, shipped in August, has yet to land on enough devices to even appear in Google’s pie charts of Android versions in use.
Google’s attempts to ease Android updates for smartphone vendors may make this problem less awful at some point. In the meantime, if you have a Pixel phone or one of the handful of others to get Pie, I suggest you enable lockdown (I have) and get in the habit of invoking it before reaching a security or customs checkpoint.