Uber tells you the license plate of the car assigned to you; this seems like a good way of preventing someone driving up and saying "I'm your Uber" if they sniff you using Uber on your phone.
Amazon might not do this yet but they could and obviously should.
People who are totally unconcerned about someone totally random showing up at their door carrying a potentially large(!) package are a whole different level of naive. Most of the world is not like your suburban home culdesac or Silicon Valley.
