[Jasper_]

What? There is no mechanism to "detect and punish rule-breakers" in either Ethereum or Bitcoin. Bitcoin's only mechanism is to push global human-readable alerts, or to pressure rule-breakers to stop through a blog post, as in the case of SPV mining: https://bitcoin.org/en/alert/2015-07-04-spv-mining.

If you define "rule-breaker" as "generates invalid blocks", then the only punishment rule-breakers receive is that... their block is invalid, they're ignored, and they get to try again next time.

I don't see any sophisticated collaboration model in play here.

> Even if the Fed required only trusted nodes... Lots of other problems -- everything from medical records to real-estate -- become a lot more tractable.

Why aren't they solved by a database and a public API? What does the blockchain add?

[masterbit]

Blockchain coordinates databases over different legal entities. That's the magic. It's still your DB in your Datacenter when you run your own node. You have autonomy over your own records with your keys. And you have visibility of all other records. A big central DB is under the control of a central body. With a blockchain the central control is / could be limited.

[bitreality]

Definitely, but this is a feature that a centralized authority like the fed would prefer to do without. Whatever technology is behind any sort of "FedCoin" would certainly not be blockchain. They will not relinquish control of their currency, doing so would make themselves obsolete.