In this paper we want to explore a new approach for security mechanisms design and deployment in the context of Internet of Things (IoT). We claim that the usual approach to security issues, typical of more classical systems and networks, does not grab all the aspects related to this new paradigm of communication, sharing and actuation. In fact, the IoT paradigm involves new features, mechanisms and dangers that cannot be completely taken into consideration through the classical formulation of security problems. The IoT calls for a new paradigm of security, which will have to consider the security problem from a holistic perspective including the new actors and their interactions. In this paper, we propose a systemic approach to security in IoT and explore the role of each actor and its interactions with the other main actors of the proposed scheme.