The person you have called is temporarily unavailable. In an individualized society, exclusion occurs when the connection fails. Those who are unreachable no longer participate in the networked society. In this book, the author examines the effects of mobile communication from the perspectives of the individualization thesis and the concepts of space and time. The isolated individual, detached from their old networks, forms new nodes in a network that knows no boundaries other than the technical ones. Technology, as a socially constitutive parameter, confronts them with ever-new developments, the effects of which are unpredictable or not intended to be foreseen. Thus, the user suddenly finds themselves caught between the pressure of constant availability and the desire to be called.