When a citizen of Rust programmers social graph uploads code, he can prove his citizenship via his id. We may not even know his name, but he can prove his citizenship. He can sign his code via his signature, even pull request in other projects. He can prove his ownership of an IT company, as it's CEO, the stock shares and what not. And he will be tied to a reputation system, so when a supply attack happens, his reputation will be tainted. Other citizens of Rust's social graph, will be able to single out the id of the developer, and future code from him will be rejected, as well as code from non-citizens.
Speaking of supply chains, how about the king of supply chains of products and physical goods? By transferring products around, in a more trustworthy way, by random people tied to reputation, Amazon may get a little bit of competition ain't it?
see also an older comment of mine https://news.ycombinator.com/item?id=38800744
All we need to do is replace the word "moderate" with "curate". Everything else is an attestation.
We don't really need a blockchain, either. Attestations can be asserted by a web of trust. Simply choose a curator (or collection of curators) to trust, and you're done.
Additionally the map of governments which accept Esthonian passport might be of some relevancy here[1].
[1] https://news.ycombinator.com/item?id=36421679