I was amused by this sign. It and several other identical signs are scattered around the odd parking lot at Northwest Trek, a wild animal park in Pierce County. Must have been an amusing conversation.
"Ok, what are we going to do about the problems in our parking lot?"
"We could create a new lot that's closer to the entrance, pave it."
"We could put up some cameras."
"Or we could just put up a sign."
"Ooh, I like it. Done."
(The location is so remote that the people breaking into cars are probably on staff. And the entrance/exit is a single road that you must traverse slowly. A single camera low enough could easily capture all license plates entering and exiting in all but the heaviest traffic times.)