Josep Rodriguez, a researcher at security firm IOActive, has discovered a technique to 'jailbreak' digital license plates.By removing a sticker on the back of the plate and attaching a cable to its internal connectors, he can rewrite the firmware of Reviver plates.The jailbroken license plate can then be controlled through a smartphone app to display any characters or image.The vulnerability exists at the hardware level, making it impossible to fix with a software update and requiring chip replacements.