From a colleague of mine and fellow Marine....
In 2003 when we and the Army 3d Infantry Division had taken down Baghdad and had truck convoys scattered all the way into Kuwait, I was a plans officer at USCENTCOM when our intelligence intercepted an order from the Iraqi insurgency commander. It was a field order to all the insurgent unit commanders and it went something like this:
When attacking supply and truck units you must be aware that there are different types of enemy forces:
1. These are the forces of the enemy armies (photos of various soldiers in their uniforms); and...
2. These are our enemies in the US Marine Corps which wears a different uniform like this (photo of a Marine wearing the newly issued USMC digital uniform).
When planning your attacks on supply lines and truck convoys ensure that you do NOT attack a US Marine unit. If you do, these supply-unit Marines will immediately act like Army infantry and they will attack you. They will also pursue you. They are well-trained and well-armed.
The other army truck and supply units will not pursue you. Attack them instead."