What rules have you broken at work?

A company I once worked for occasionally did work at a large industrial site where they were really sticklers for rules, things like hard hats and steel toe shoes. A trip there usually involved stopping at a guard shack and answering questions such as "do you have any drugs, weapons, or video cameras in your vehicle?". Glass containers were another item forbidden. I got sent there on a few occasions and I always lied about the boots and never wore a hardhat any longer than necessary to get past security. On at least one occasion I went on my personal truck and was allowed it drive it inside one of the buildings, with an escort of course. I'm reasonably sure I had at least two of the forbidden items in my truck, on top of not having steel toes and not wearing a hard had. My job didn't involve working around any dangerous equipment so there was never any real danger.