It's also often the case that most participants are playing fair, but there are one or two who step way over the line. A friend of mine used to work in a place selling baked goods. One of the perks was that if there were any cookies left over at the end of a shift then the staff could take some before the batch got dumped. This went on happily for years until one day an email came in from head-office, stating that all food was to be dumped at the end, no freebies, etc. turned out that a manager at another store had been deliberately baking up huge batches of food to be taken home at the end of the night (think a few crates of cookies to cover the neighbours kids birthday that weekend), far beyond what had been considered fair game by the company.

These kinds of perks always seem to get ruined by that one idiot who goes overboard.