In this paper, we address the exploitation of computer vision techniques to develop multimedia services and automatic monitoring systems related to the security and the privacy in public areas. The research is part of a two-year Italian project called LAICA, intended to provide advanced services for citizens and public officers. Citizens want fast and friendly Web access to public places, to see the environment in real-time without violating the privacy laws. Public officers and policy centres want a fast and reactive monitoring system, capable to automatically detect dangerous situations, given the huge amount of cameras that can not be monitored simultaneously by human operators. In this work, we describe the project and the defined methodologies in multicamera video mosaicing, people tracking and consistent labelling and access to processed data with face obscuration.