Real facts which I presented with words "due process." What is difference between these machines and a strip search?
I guess I don't understand your point. If you have a choice between walking through a metal detector and walking through a body scanner, and you deliberately choose to go through a body scanner, then how does "due process" apply when you voluntarily chose to go through the scanner?
When you go to the airport, it should be no surprise that you have to clear security first before boarding the airplane because you agreed to that when you purchased your tickets (whether or not you read the fine print doesn't matter, as established by legal precedent on countless occasions). If you do not want to go through security, then you can turn around any time before you reach the checkpoint and no one is going to force you to submit to any airport security screening. Again, where is the "due process" controversy?
Due process violations apply when the government restricts your freedom without establishing probable cause/reasonable suspicion and/or accuses you of committing a crime without sufficient evidence. None of that applies at the airport UNLESS airport security screening reveals the presence of a firearm, IED, or other violation of law. Instead, you are giving your implied consent to an administrative security search when you walk up to the checkpoint and hand over your boarding pass to the ticket checker at the checkpoint entrance.
This is all pretty fundamental.