The technologies of mobile communications and ubiquitous computing are p- vading our society. Wireless networks are becoming the nerves of our territory, especially in the urban setting; through these nerves, the movement of people and vehicles may be sensed and possibly recorded, thus producing large volumes of mobility data. This is a scenario of great opportunities and risks. On one side, data mining can be put to work to analyse these data, with the purpose of producing useful knowledge in support of sustainable mobility and intelligent transportation systems. On the other side, individual privacy is at risk, as the mobility data may reveal, if misused, highly sensitive personal information. In a nutshell, a novel multi-disciplinary research area is emerging within this challenging con?ict of opportunities and risks and at the crossroads of three s- jects: mobility, data mining and privacy. This book is aimed at shaping up this frontier of research, from a computer science perspective: we investigate the v- ious scienti?c and technologicalachievementsthat are needed to face the challenge, anddiscussthecurrentstate oftheart,theopenproblemsandtheexpectedroad-map of research. Hence, this is a book for researchers: ?rst of all for computer science researchers, from any sub-area of the ?eld, and also for researchers from other disciplines (such as geography, statistics, social sciences, law, telecommunication and transportation engineering) who are willing to engage in a multi-disciplinary research area with potential for broad social and economic impact.