This is all because of Muslims.
Mohammedans are the excuse for it, anyway. What it is for is the routine humiliation of the citizenry. It gets folks feeling more like subjects than citizens. Once they are all installed in all the airports they will start to go in at federal courts then federal offices everywhere then the states, feeling left, will start putting them into state courts and offices and they will go into county offices, too. And these things will be coupled with other sorts of scanners so that nothing on you will be unknown.
No. It's all because of frightened security-first statists, lobbyists employed by the security industry, and Congressional Democrats seeking to expand the Federal employment rolls and their own voter base. Don't blame Muslims for what we did to ourselves through our own government.