Seen in Narita Airport:

The English text of the sign reads: “If you don’t mind to discard the prohibited items such as knives, scissors and lighters. Please put them into this box.”

I wonder if anyone ever has? I assume that the items already within were planted there in advance. What would motivate someone to drop a forbidden item in the clear box rather than in a nearby garbage bin? (I can see the negative motivation, not to drop things in the box, because other people will see that you didn’t know not to bring those “dangerous” items along.) If the box’s purpose isn’t really to collect items, what is it? Perhaps it serves as an eye-catching early alert (before entering the security line) that allows people to save face by warning them that some items must be disposed of?