[jarek]

That might make it a viable single-identity system. As long as you only want U.S. users.

[wmf]

If NSTIC works, it's likely that other countries will adopt it.

[jarek]

I can already see the early adopters: Russia, China, France, Germany...

Even if you do it so that the actual data stores are separate and you manage to keep the APIs the same, lots of countries will have huge issues with adopting U.S. policies.