In Arizona, it is against the law for bars and restaurants to serve a customer to the point of intoxication. It is also against the law to serve alcohol to a person who is already drunk. These laws are in place because the restaurant or bar is in the best position (and has the necessary training) to determine when a customer is drunk. The establishment obviously makes money when the customer continues to buy alcohol, so lawmakers wanted to ensure the bar/restaurant does not have an incentive to over-serve people. They are therefore able to serve alcohol to customers, but they must also take responsibility for ensuring the safety of the general public by cutting off intoxicated people and preventing them from driving home.