Why is delivery to balconies needed?   What problem is this solving?   Deliveries by Amazon are so fast using existing services that you often receive them within 24 - 36 hours in urban areas.

I can see the benefits of drone deliveries to remote locations that are not well served by delivery services.   For example, delivering medicines and other important goods would be a real boon for remote places to supplement whatever service is in place (if any).

But this?  This makes no sense for the consumer and creates the real possibility of privacy violations.   You have to wonder who is driving this -- the CIA and FBI?