They chosen at random, told to bring their passports, and the rest is history.
It was a setup to make the Iranians look reasonable and the Americans to incompetent and cowardly.
They've always been around. John Kerry, Tulsi Babbard, Pete Buttigieg.
@realDonaldTrump has said the following several times:
He means stuff like this.
Flat-out aiding and abetting the enemy.
The navy covered it up, because that's what the military always does.