Governments around the world propose to improve urban life by creating smart cities filled with sensors and other digital technologies that would collect large amounts of data about citizens and their activities. Ideally, smart cities would use the information they gather to enhance the urban environment and improve the quality of life of their people. But concerns about privacy, questions of ownership, and other issues have made smart city technology controversial. This article suggests that, when considering the future of smart cities, we should look to libraries for inspiration.