Cheer up, commuters...

...before you get detained. Facial ticks and expressions are now being observed by "behaviour scanners" at more than a dozen airports around the US. Signs of stress in the faces of would-be-passengers will be cause for security personnel to question, search, and detain you.

Of course, there is no such thing as a universal indicator in everyone's face that would reveal they are lying or under stress. Furthermore, security personnel making minimum wage in airports have proven ineffective at monitoring x-ray machines, let alone being asked to function as behavioural scientists. So what is the chance of this measure curbing terrorism? Is it greater than the chance of giving citizens a false sense of security?