Well, the guy was flying his drone in what appear to be a pubic area. The fisherman IS an ahole...

As far as shooting a drone hovering over your place UNTIL laws are changed you dont own that airspace and it is not legal for you to destroy that other person property. I have to agree it would be intrusive and the law has to catch up with the technology and eventually will. Still I cant see how said law will allow you to shoot the drone...
AND since the law is so greyish on that sense, that is why I am sure they went after the gun discharge in city limits as it is a clear law. If you are worried about drones I think all you could do right now "legally" is to get some sort of microwave directional transmitter to jam the drone transmit/receive signal and that will probably take it down undamaged, then take possession of the drone that drop in your lawn that you own... I am sure someone is working on such transmitter if it is not already done...