Righty -Tighty, Lefty -Loosey 

Reading a book about NYC subway.

Interesting fact: old subway cars used regular light bulbs for normal lighting and special left-handed screw threaded bulbs in emergency lighting. The regular bulbs were always on, and because of that nobody could steal them easily (they were too hot). The emergency lights were threaded incorrectly, so the potential thieves would have to figure out how to unscrew them first, and even if they succeeded, they would not be able to use the bulb at home. This is kind of like special coat hangers and non-standard linens in hotels. Hmm, I can’t remember any other uses of non-standard equipment for theft prevention.