Information and communication technology (ICT) is producing urban environments that are quite different from anything that we have experienced before. Cities are becoming smarter (or rather their population is becoming smarter) and can automate functions serving individual persons, buildings and traffic systems. At the same time, sensors streaming data, are giving rise to entirely new forms and patterns that enable us to watch how cities and their populations are responding in almost real time. Big data, open data, wireless sensor networks may represent basic tools for re-thinking our development model, decoupling economic growth from environmental degradation; re-designing our planning tools in face of the new challenges that cites have to deal with; creating inclusive and sustainable communities. The new ICT capabilities will allow the rising of a new dimension of the urban social capital and a new consciousness of citizens in the monitoring of the evolution process of the city.