RE: Poaching...
If you're going to do anything to the tires, just remove the valve core, this does no property damage. I would recomend not taking the law into your own hands, If you're standing next to some dudes truck with a big grin on your face, four flat tires, and 'waiting' on a GW to show up, *Deleted* gonna get out of hand real quick.
Take pictures, hide in the weeds, whatever it takes, but contact the law first.