Originally Posted by
HkCaGu
The U.S. government does not track whether its citizens are outside or inside the country. It only matches arrivals through manifests of ships and planes, and requires airlines to report U.S. citizens' departures, and whatever itinerary information associated with their arrivals.
So the government would not care if you left by air, then returned by land or sea without a passport scan, and then tried to board another international flight to leave again? Or would the system be flagged because there was no record of you returning before departing again? (assuming a US Citizen/LPR)