I was just looking at NFC smart locks but I'm realizing whenever that stuff becomes easier to use and more commonplace it's going to all be tied to servers so some corporation can remotely unlock your stuff at the request of the government or because someone hacked it. It's so so easy to make a product that can't feasibly be tampered with or violate privacy or anything like that, but all these companies went ahead and connected every conceivable appliance in a home directly to their internet servers (and they didn't even make it convenient by using a single shared standard, every company has their own incompatible smart home ecosystem!).