That is before we get to the security acceptance of anonymous autonomous UAS flying 5lb packages around major cities like DC, New York or London.
There is also the social disturbance/invasion of privacy topic you read about. Camera toting drones over-flying private areas, taking photos/spying, and then posting them on some titivating 'no-one gives a toss' social website. If you could trace the owner you could take some action, especially if it dumps itself on your property. One sure way to capture said pesky intruder is to engage the use of a trusty shotgun. It will happen, especially in some of the more outlying properties where people like to 'look after themselves' and not trouble local services with trivial complaints.