I'd love to see some sort of crowd sourced solution for this system where Amazon offers up what it sees as the biggest technical/legal limitations and asks the internet for its solutions.

So far in just the HN threads, I've read some pretty innovative ideas (QR code landing pads that homes can setup for the drones). I'm pretty sure with the hive mind of the internet this problem can be solved by the collective engineer/lawyer/politician/etc

We put men on the moon I think we can put amazon packages in people's backyards!