Quoted in <https://www.schneier.com/blog/archives/2017/12/amazons_door_lo.html>: The Key-compatible locks are made by Yale and Kwikset, yet don't work with those brands' own apps. They also can't connect with a home-security system or smart-home gadgets that work with Apple and Google software. And, of course, the lock can't be accessed by businesses other than Amazon. No Walmart, no UPS, no local dog-walking company. And so Amazon becomes a gatekeeper (literally) for access to your very home.