As I remember, this was discussed sometime ago on HN. I dont remember exact link posted on HN but here is techcruch article of a start-up that was discussed on HN
http://techcrunch.com/2013/10/14/australian-startups-zookal-...
http://techcrunch.com/2013/10/14/australian-startups-zookal-...
I'm certain drone delivery has been discussed by many countless people, most of whom the acronym HN means nothing to.