and if they do cross my property line they can be held responsible, including me shooting it out of the sky.
Can you shoot down airliners who cross your property lines?
You actually don't own all airspace over your property. There has been a SCOTUS ruling on the matter.
Thus, a landowner "owns at least as much of the space above the ground as he can occupy or use in connection with the land," and invasions of that airspace "are in the same category as invasions of the surface.
It is clear that the land owner does not own navigable airspace. Navigable airspace is defined with respect to fixed wing aircraft, the FAA has done that, it is unclear as to what navigable airspace means with respect to small drones. There is even a clause that allows helicopters to fly below normal flight minimums. There still needs to be legislation defining exactly what "space above the ground as he can occupy or use in connection with the land" legally means. Having to fly comercial drones at fixed wing minimums would render them useless. This is one of the reasons why the FAA is holding back on allowing commercial drones as the laws backing them up are unclear.