With mail, the only information that is verifiable is the address that received the mail.

The return address can be made up. Although the general area it is sent from is recorded in the form of zip code.

The contents of the letter are also not known.

So even if that info got out, there’s really not much information beyond the fact that mail was received, and we probably know who sent it.

Thats a world of difference from cryptographically signed transactions between known parties with known amounts.

There's a reason why the saying goes as "follow the money" and not "follow the mail". Think about why and you'll understand why CBDC is Orwellian worst nightmare.

If you're interested in the technical answer, this is the SCOTUS case law that decided that postal mail was subject to the Fourth Amendment:

https://en.wikipedia.org/wiki/Ex_parte_Jackson

one secret there is, they can photo record every source addr<->dest addr from the post item face, for some or all of the delivery, for years and years without fail, keep those records, and then do investigative work from that.

They never open the package, and technically, they are quasi-public.

Public enough that they can't play fast and loose like everyone else, but private where it matters in terms of not having literal Federally administered databases all just eafer for the reaping.

The USPS isn't quasi-public, it's fully public, an “independent” (meaning it has an Presidentially-appointed, Senate confirmed board with limits on degree of single-party domination) federal executive-branch agency.

The fed is quasi public too? It’s actually less public than the postal service, the postal service is a fully public agency, the fed is partially governed by private banks.

> the postal service is a fully public agency, the fed is partially governed by private banks.

The Fed is fully governed by a federal agency. (The Fed Board of Governors).

The individual regional Fed banks are private-public hybrids, but they don't govern the system.

Nonetheless, given that the individual regional banks are have directors that are elected by the member banks, control over certain levels of fed policy are in a sense private, whereas that is nowhere true for the postal service. At least not to my knowledge.

Right. So, couldn't the central ledger be similar?

If they don't require KYC for accounts, and maybe even use privacy tech like Monero or ZCash, then sure. How likely do you think that is?