The increasing complexity shown in Smart Environments, together with the spread of social networks, is increasingly moving the role of users from simple information and services consumers to actual producers. In this work, we focus on security issues raised by a particular kind of services: those generated by users. User-Generated Services (UGSs) are characterized by a set of features that distinguish them from conventional services. To cope with UGS security problems, we introduce three different policy management models, analyzing benefits and drawbacks of each approach. Finally, we propose a cloud-based solution that enables the composition of multiple UGSs and policy models, allowing users’ devices to share features and services in Internet of Things (IoT) based scenarios.