As a result of the recent explosion of sensor-equipped mobile phone market, the phenomenal growth of Internet and social network users, and the large deployment of sensor network in public facilities and outdoor environments, the "digital footprints" left by people while interacting with cyber-physical spaces are accumulating with unprecedented breadth, depth, and scale. The technology trend towards pervasive sensing and large-scale social and community computing is making "social and community intelligence (SCI)" (Zhang et al. 2011), a new research area that aims at mining the "digital footprints" to reveal the patterns of individual/group behaviours, social interactions, and community dynamics (e.g., city hot spots, traffic jams). It is believed that the SCI technology has the potential to revolutionize the field of context-aware computing, will transform the understandings of our lives, organizations and societies, and enable completely innovative services in areas like...