I think it would be reasonable to treat a drone with a camera as a proxy for the operator. So if you're doing something with a drone that you couldn't get away with yourself, it's going to cause problems. In a 'stand your ground' state, I suppose that shooting it down would be permissable, but I wouldn't want to go to court as the test case. That's the problem with drones right now - there's very few laws to govern their use, so everything will have to be litigated to determine who can do what. Luckily, I don't have a problem neighbor and the paparazzi have been leaving me alone lately.