if they don't respond correctly, take whatever steps you feel appropriate.

So ANYBODY can determine if ANYONE ELSE'S response is "correct"? And they can do whatever they want with the box, if the response didn't meet what they wanted it to be?

Sure, I can understand if something is dangerous or poses a threat. Common sense is a wonderful thing. But if someone plants a box, just because you don't agree with the placement does not give you Letterboxing Police Authority.