But how do you actually trust them?

There's almost no time investment in building onlyhumanhub. It's only a few months old (based on the copyright), have effectively a text-only homepage, and account creation which I assume allows you to upload photos of your passport and link your existing social media profiles.

There are so many ways that could go wrong, from this being a phishing attack to this being a well intended project that happens to create a database linking passport IDs to all of a person's social media accounts.

The idea that they may eventually offer a social media platform that doesn't require public use of your real identity is all well and good, but they're still a honeypot for doxing.

Well, I built the site.

I agree that trust is a problem. I try to be as transparent as possible around how your passport data is used and what is stored in the database. Far more than what ordinary banks/trading apps say when they ask you for a passport.

Hah, well sorry for my confusion there! I didn't realize it was yours so that definitely clears up why you'd trust it.

While I have you here I am curious what's evolved in validating passports? Is it as simple as a unified API run by some service to validate, or an API per country?