Tipping may be one of the most controversial payment practices in America that is also legal. It's messed up that servers, as well as the runners and bussers and bartenders, depend on tips for the bulk of their paycheck. Some restaurants increase their prices and do away with tipping, but that also makes people upset. Unsurprisingly, the sort of people who tip badly also want to have a sense of control over the person bringing them food. Tipping is psychological warfare.