Social Networks, Mobile Internet and Location-Awareness nowadays can be combined into a new type of ubiquitous environments (“Future Internet”, location-aware social networks), where security, privacy and trust are very important problems, especially for end-users. These are relatively new research topics in ICT, however they have already become the most remarkable phenomena in the Internet during the first decade of the 21st century. Indeed, end-users should be able to use, compose, adapt and personalize ubiquitous services, for example by defining and composing user-centered service policies (including security, privacy, access control and trust policies). This opens new opportunities for innovative scenarios of end-user services and service compositions.