Four states are ordering people to wipe the grins off their faces in their license photos. “Neutral facial expressions” are required at departments of motor vehicles (DMVs) in Arkansas, Indiana, Nevada and Virginia. That means you can’t smile, or smile very much. Other states may follow. The serious poses are urged by DMVs that have installed high-tech software that compares a new license photo with others that have already been shot. When a new photo seems to match an existing one, the software sends alarms that someone may be trying to assume another driver’s identity.