I'm hoping eventually the FAA will come up with some common-sense rules on when it is appropriate to bring a UAS down to earth with a shotgun blast. Questions that need standardization (and modification from current rules) include things like:
When is it ok to shoot down a UAV over your own property? Currently if its your own UAV, maybe. If it isn't, no.
When is it ok to shoot down a UAV that is not on your own property? Same thing, what if it is your UAV and what if it isn't?
When is it ok for a landowner to destroy/disable a UAV over their own property that may be committing a crime (filming a minor thru their window when they may be changing clothes, for example)?
I figure any UAV within 300 ft AGL over my property ought to be fair game, however I am also quite sure that I have no idea what may or may not have happened to any UAV that may or may not have been over my property officer and no you may not search my property or enter my house without a warrant looking for some creeper's peeping tom UAV. I just don't know what you're talking about, no UAVs here officer.

There are already 2 types of counter-UAV systems that may or may not be legal. Directed energy (likely 2.4ghz and/or GPS jammer) may be illegal, however "inadvertent" mid-air collision with a property owner's own UAV, or the net being carried by said owner's UAV, would more than likely lead to a liability finding against whoever is operating an intruder UAV over a populated area (my house). I have 3 little kids who would likely be badly injured by a falling UAV so reckless endangerment of a child might even apply, should a UAV fall (for whatever reason) on my property.
We BADLY need regulations and updated laws in place to encourage lawful private and commercial use of small UAVs, while protecting landowner privacy and strongly discouraging perverts and paparazzi intrusion. The creepers out there are making it harder for legit businesses to use these things.