The security concern (for the drone and the contents) is a bit overblown to me. What about all those ATM bank machines in all sorts of "insecure" places? We've somehow figured out how to keep money inside a machine that is unattended. The amount of theft that occurs on those things is minuscule and banks put the cost of such theft into their profit calculations.

The Amazon drone won't take off unless you confirm in advance (using the app) being able to accept the package, and you need to enter a code at arrival for it to release it to you. I am sure the drone can call for help, and keep lots of video and other evidence of what happened to it.

Ultimately, Amazon just calculates the loss of 1/10000 drone packages into their profit calculations.