I see a lot of value in a network where I can be confident I am talking to real people.
As a user I can't do anything related to the passport stuff and I know many people who likewise wouldn't be interested in doing that, because we live in the states. A more "normal" approach here would be to use one of the government ID verification systems for your state ID. Most of us are willing to expose that information, since it's what you show when you go to the store to prove your age/identity.
I’ll definitely look into this. But starting with them would limit me to the US only (I’m sure other countries have similar things, integrating each would take a lot of work though). I want to start with passports because they are a true multi national document.