This short story happened right about the time they changed the instructions to say that we had to bring our own lunches in unlabelled backs and that we should not go out for lunch.
While I was doing attendance, I got thirsty, saw a vending machine, and as I looked for change in my pocket, there was a bother who told me we weren't supposed to buy anything from the vending machine; he was making a big deal out of it. I told him: Do you see a sign? Is it out of order? Nope... no sign, and its working... how about I make sure of that... than I put change in the machine, got my drink and said: Sure enough, it is working!
Next day, there was a big yellow tape around that very machine. The following years though, they dropped the ban.