Colombo, the focus of our exploratory work on mobile network big data, is a tiny town by global standards: 550,000 people. But our analyses show that the surrounding area is tightly integrated contributing over 54 percent of the daytime population of the city, but contributing little or nothing to the services the commuters must be provided. A former Mayor once told me that he had thought of using the dormant power of the legislation that established the Colombo Municipal Council to establish tolls at the gates of the city. Appears this is not a problem limited to Colombo. Current debates about the efficiency of urban governance gravitate around the ‘fit’ between the size of the administrative boundary controlled by a city mayor or governor, and the actual number of people who live in the ‘wider functional metropolitan’ area.