Living safely and securely is a basic human desire with many facets. Its satisfaction has psychological and societal, but also technical, legal, and economic implications. Moreover, rapid progress in networking sensors producing an ever increasing diversity of information has profoundly transformed the notion of public security. This technological revolution is driven by algorithms for extracting high-value information from sensor data streams - an enabling technology rooting in the Aerospace and Electronic Systems community. Besides discussing general design principles of security assistance systems, it is a serious concern to pinpoint also societally relevant challenges that are pressing and to be solved in an interdisciplinary approach