The techniques of this disclosure temporarily disable biometric recognition in a device to prevent unlocking of the device. The user registers one or more specific facial expressions as do-not-unlock expressions. If the facial recognition tool recognizes a registered do-not-unlock facial expression, then unlocking of the device is disabled until preconfigured conditions are met. The user can also register context, e.g., location, time, environmental parameters, etc., that makes the device ineligible for the biometric unlock
