Lockdown
With smartphones, lockdown is a mode that disables biometric access to the phone (e.g., fingerprint or Face ID) and only allows the device to be unlocked using a passcode. This feature is helpful for users who don't want police or other government agencies viewing their phone's contents.
For instance, police may ask you to unlock your mobile device to verify you were not near the scene of a crime. Depending on your location in the world, police may force you to unlock a biometrically protected smartphone. However, in many areas, a user cannot be coerced to enter their passcode because they are protected by self-incrimination laws. Essentially, if you enable lockdown, the police cannot force you to unlock your device.
In the United States, for example, the Fifth Amendment extends this protection to individuals. However, while they cannot be compelled to enter a memorized passcode, this law may not apply to biometric access.
How to enable lockdown
Enabling lockdown on iPhone
On an Apple iPhone, press and hold all three buttons on the phone (power, volume up, and volume down). If done correctly, the screen shows options to turn off the phone, display a medical ID, or make an emergency call. If this screen is shown, even if you hit the cancel button, the phone is in lockdown.
Enabling lockdown on Android phone
As many companies manufacture Android smartphones, there are various methods to enter lockdown. Below are two common ways to enter lockdown on an Android device.
Google Pixel phone
Press the power and volume up buttons at the same time. Tap the Lockdown option displayed on the screen (as shown in picture).
Other Android phone
Press and hold the power button. Tap the Lockdown option displayed on the screen.