A medium-of-exchange that isn't private by default would never work in today's regime. If you treat privacy as "expert mode", you guarantee surveillance wins by default. You need privacy & fungibility by construction, not by habit. If surveillance can reliably distinguish "good" vs "bad" coins, policy and perimeter will always drift to "good only". All transactions must look like each other: - No transparent subset as "legacy mode". - No visible amounts or script opcodes per tx. - No address types that reveal more metadata. This collapses the main control trick: "we only KYC or de-bank these flows". Make the policy choice binary: ban the entire asset, or accept that everything is indistinguishable. This way you have no taint wars, no heuristic creeping. Privacy-by-default vs opt-in privacy is basically the difference between: - You're dark unless you explicitly shine a light. - You're lit up by default unless you personally crawl around the interface turning lamps off. You don't get tax exemptions by begging corrupt politicians, you get tax exemptions by implementing privacy by default. Privacy by default protects the lazy, the busy, and the non-expert. Opt-in privacy protects only the most disciplined, and even then often only cosmetically - while turning them into a distinct, more interesting group. https://controlplanecapital.com/p/bitcoin-will-fail-as-ma…