The Social Internet of Things (SIoT) is a paradigm born to provide information of interest and discover services smartly without human intervention, so as to overcome some of the most important challenges of IoT networks, such as scalability and heterogeneity of systems. Social Objects are able to establish social relationships with each other based on the social relationships of their owners in Online Social Networks (OSNs). In such a scenario, providing security and reliability of the service is an important research topic. Furthermore, considering the malicious behaviour that some Social Objects might have, the problem of trust assessment remains of paramount importance.