[supercat]

Maybe as a cost-cutting measure they need to stop letting their equipment walk out the door.

[Calvin Locke]

I watched one of those "how it's made" shows on ice cream. After each carton is filled, weighed, sealed, etc, it goes through a metal detector. Besides the obvious (ingredients), it's also a great way to check for a machine that's spitting metal before a total breakdown.

While a metal detector would require extra checking for people that are supposed to have metal in them, it wouldn't help for extra metal, non-metallic leavings, etc.