California Vehicle Code Section 14604 states that "No owner of a motor vehicle may knowingly allow another person to drive the vehicle upon a highway unless the owner determines that the person possesses a valid driver's license that authorizes the person to operate the vehicle." As the registered owner, you are responsible for anyone who drives your vehicle; whether it be a relative, friend, or acquaintance. If your vehicle was taken without your permission, you must file a stolen vehicle report and the person will then be charged with a crime and may be arrested.