not just the us.

You can't take a pair of nail scissors through customs. But once into the duty free zone you can buy glass bottles full of flammable liquids - hell it's practically compulsory, razors, cigarette lighters - you know all the stuff you can't take through security.

At no point has logic ever been applied to airport security.

Go first class and they will give you sharp metal knives and glass bottles. 'cos first class passengers could never be hijackers.

If I ever stopped laughing I'd probably have to cry.