If you set up any form of security that will intentionaly cause harm to someone it is considered booby traping.
O'K i have to ask :?: if you install Razor wire or Barbed wire on your fence is that also booby trapping :?: because it for sure will cause intentional harm. I know it wouldn't work on a mail box, which was the original post. Again i'm so glad i live where i do, in an area so peaceful,(want buy a little house 1340 sq ft and BIG shop 2400 sq ft), that it makes headlines when there is a B&E. Around here about the only calls the cops (2 in all) is when some farmer or employee get drunk and goes off on his wife, and the word spreads like wild fire and he can't hold up his head when out in public for the next month.
Zip.