After the crime rates started to rise during the industrial revolution, fewer and fewer human police officers signed up to take on the mean streets of the growing cities. As a result, the government developed a legion of law-enforcement robots programmed to carry out the law in a way that the best human police officers did. The robots were friendly, greeted civilians that passed on the streets, and carried out the law with all the means necessary. The cities grew fond of their neighborhood police-bots, which had proven to be the most effective and corruption-free law enforcement system in history.