I personally wouldn't have the warnings plastered up, I understand why someone would but personally it's not my style.<p>I'm generally a nice person, however I typically follow a one-strike and you're out rule. I don't expect second chances, and I've typically worked in industries where second chances are rare to come by when you make a mistake personally or professionally. I choose not to work store-front or public relation jobs. I can handle a person, I can't handle a hundred. I know if I owned a store or food place, I'd likely have rather draconian rules even if they're not on the walls.<p>It sounds like the diner owner in question may be of a rather anti-social disposition, but he chose the wrong job for it. I had the luck of being in jobs where my attitude rather helped, I remember having to tell one person that what they wanted was illegal (against the building code), that I wouldn't touch it and if they found another guy to do it that he'd be liable and the customer would, at best, have to pay out thousands to have the job redone when they went to sell the house, and at worst could be prosecuted too. Telling that to someone got me their respect, if I'd basically said the same Go F Yourself to a customer in a store, I'd have likely lost their service.