[HappyDreamer]

With "refused access", you mean those people weren't allowed to enter the US?

They had to stop at the border, and take the next flight back home?

(But what would happen, if one didn't disclose one's social media accounts and other things, when leaving the US)

[grishka]

I've been to the US and there's no passport control whatsoever when you leave. You don't ever see a border guard on your way out — you go through security at the airport and then straight to the gate.

The real problem is that they now require social media handles on the visa application.

[mrunkel]

Not 100% true. There are random and targeted searches of people boarding flights and requests for ID from CBP officers.

The usual reason given is searches for large sums of cash.