These examples say more about the sad state of the world we live in than the feasibility of the use cases. I didn't say these things were impossible, just that

These examples say more about the sad state of the world we live in than the feasibility of the use cases. I didn't say these things were impossible, just that they are about collecting debts, so I've tried to respond below by showing how they allow parties to collect debts. - Personalized tracking for marketing and advertising use cases is about changing subject behaviors, so that they spend their time and energy on things that other people want them to spend it on. Grocery store "loyalty" cards are one of many examples of how we cede agency -- in this case, allowing a corporation to assign a debt in the form of coupons that predispose us to buy a particular item. Does the 49 cents off the chocolate treats make the 30g of sugar more healthy? This is textbook predatory behavior. - Phone numbers are a thing because we rely on centralized communications where the phone number is associated with an account billed monthly for collecting a usage debt. However, with technologies like torrents and WebRTC this is changing. In the future, maybe you provide each of your friends and family with a unique signature that allows them to look you up on the net? If I could give up my phone number, it would certainly cut down on all of the robocalls and spam I get every day. This isn't novel or weird: many people already hand out email addresses of the form name+safeway@place.com to bucket spam. - A physical address is a weird example because it identifies a physical location, not a person. I am not my home address; I just sleep there sometimes. Sometimes, I'm sleeping somewhere else. - Club membership? That's easy - if you're paying for membership, then they need an account id to collect the debt for your membership. If you're not paying for membership, they don't need an ID. There are lots of clubs or meetups that don't require IDs -- the evening tech meetups/bar crawls around Seattle, for example. - Passports, Customs, and Borders exist as a mechanism for the state to collect taxes on goods crossing international borders. Not the only mechanism, just one of them. Governments are currently struggling with goods and services crossing international borders digitally bypassing these checkpoints. I'm not sure, though, why you think passports are a humane thing -- we put tags on livestock.