Yes, but the Truck is parked on the employers property.
And if I got fired for sending my liberal sister a list of reasons why we SHOULD go to War with Iraq and did so on a company computer you would support my liberal boss for firing me?
If the employer provides a place for employees to park, he can not discriminate against an employee because of the views he holds (or what "statements" may be on his means of transportation). Parking on the employee lot does not indicate that the employer is endorsing the opinion of the employee.
And if I got fired for sending my liberal sister a list of reasons why we SHOULD go to War with Iraq and did so on a company computer you would support my liberal boss for firing me?
If your company has a policy against using thier property for personal matters, then yes, they have every right to repimand you / fire you for theft. Important is that the company must have a policy against this and it must be uniformly enforced. The company may NOT chose which "opinion" can be expressed.