This thread is awesome. Bravo Sushi, you need to add a note saying "same here - someone filled the fridge with home food and binned mine - this will also not be tolerated" 
In my office days I had a fabulous but very badly paid job - it was a bit like Bear Grylls' The Island - paradise from the outside, horrendous if you're actually trying to live on it. It meant that in general we all pulled together. We had a fridge, free tea, coffee and milk from the company, toaster, microwave, proper coffee pot, even a little sandwich maker, and all was well in paradise for a long, long time.
However it was not to last. A couple of of new people started and used the facilities with gay aplomb, crumbs everywhere, repeatedly setting off fire alarm with burned bread, finishing milk, not washing up, cooking fish in the microwave and not cleaning it after (bleugh) etc. The receptionist Jen, who was also the PA and the HR (is that even legal?) got totally fed up and took it upon herself to police the kitchen. She was actually a darling but quite embittered and got everyone's backs up but was in an impossible position because she had so many hats.
She got more and more annoyed, PA notes multiplied, got defaced etc etc etc, but because we were all cool creatives our attitude was 'yeh, go burnt sandwich maker! Stick it to the man!" (yes we were twats but there's a kind of hilarity in it all)
Until one day we came in to find all the amenities except the fridge and kettle had gone. Turns out Jen OWNED them and had got so fed up she'd removed them all. We were a much more chastened office after that.
Then The Porridge Milk scenario happened (god this must be common) and the Hell of Old Rotting Food. After various 'please don't use the milk for porridge' 'please chuck away your old food' emails, Jen lost it again.
The note read "The next time someone uses all the milk in the porridge or leaves rotten food in here, I'm taking the fucking fridge home"
Even the 'children' in the office behaved after that.
I asked her months later and she admitted she didn't own the fridge OR the sandwich maker etc. She'd hidden them all in the basement storage room.