this is retarded. there is no good reason to do this. if there is a good reason, i really don't care and would rather live in a freer society with slightly more risk.
"police state reduces crime" okay i do not care.
even their stupid IMS machines are just calibrated for lots and lots of type II error, and i don't believe they've actually ever caught anyone.
p.s. the sixties hijacking thing wasn't for purposes of terrorism. it's also why federal marshals started traveling around on planes.