I got my bike stolen in a similar situation and it hurt, like losing an old friend. But looking to settle it with a gun is a REALLY bad idea. Even on your own property you are opening up yourself for serious jail time.
That depends on the state that you live in to if you will even get in trouble or not. Just remember to shoot to kill and not to wound. Damn civil suits will kill you. That is of course if you want to take it that far. To make it worse the culprits probably live within a mile of your house.