Rules About Refills At McDonald

We were driving up to visit my parents this weekend, when we pulled over for a McDonald's pit stop. This sign floored me. Have we sunken this low as a society that we actually have to hang a sign like this? What cracks me up is that behind this sign is a story. This particular McDonald's obviously was having a problem with someone who thought buying a large Coke at McDonald's entitled them to a refill for life.