SPOT will be sooo easy for bad guys to hack (assuming there is something about a bad guy that would be detected by a secondary inspection that wouldn't be detected by the regular screening procedure).

You send a bunch of nervous-acting guys in turbans carrying manicure scissors or lighters on ahead of the real bad guy, a white guy in a suit.

You send in a bunch of hippies wearing patchouli oil and carrying baggies of oregano on ahead of the real dope smuggler.