In the UK it is illegal to shoot at ANY airborne vehicle including drones. I suspect it is the same across the US. I wonder if defensive barrage balloons would be classed as illegal.

What some people will do to make a sale. Anyway SG would be cheaper and in any case I don't have a recipe for a drone so I would not kill one.

It would be treated exactly the same as shooting at an airliner and they would probably try some terrorism charges as well it the drone was any way official.

Having said that, planes landing at Heathrow are fairly often found to have crossbow bolts in the wings.