People are always pinching my milk despite it being in a bag tied up. The company provide uht milk but I buy my own so now i take the label off the bottle and put a note on that it is special hormone milk and shouldn't be consumed by just anyone. So far so good!
I always wonder if people who go to these lengths to mark/protect thier fridge stuff realise this 99% of the reason your stuff gets nicked.
People generally do this to wind you up the more you try to protect it the worse it gets.
I've left half a dozen cans of monster in the fridge for weeks not one touched.
The dude who drilled his milk bottle to put w padlock through it somone spent ages slowly draining it through the leaky hole and put it back empty just to watch him rage