Software as a service is the current trend in software deployment where an application is hosted as a service and provided to users across the Internet. This model inspired the collaboration as a service, where a service provider offers collaborative and social network services. The social relations provided by the social services are important to push further the collabora- tion between people. It is important to evaluate the location of actors in the network to understand networks and their participants. Measuring the network location is finding the centrality of a node. These measures give us insight into the various roles and groupings in a network, where are the clusters and who is in them, who is in the core of the network, and who is on the periphery? However, having a social service provider arises privacy and censorship issues [1], since it can exploit the whole social network relations and interactions among the users. In order to overcome these issues, new decentralized approaches were proposed. They provide collaborative services without a dedicated service provider. Users can create their own collabora- tive network and share the collaborative services offered by the system using their own resources. Skype [2] and Distributed Version Control Systems (DVCS) [3] (e.g. Git [4] and Mercurial [5]) demonstrated that it is possible to communicate and share data without the need for a collabo- ration provider. Although distributed systems provide the required collaborative services, they do not provide the social services offered by centralized systems. In distributed systems there is no central point with a global vision of the social network or which is able to build and reflect the social relations among people. Other approaches use private peer-to-peer networks [6] where the resources and infrastructure are provided by the users. Groove [7] is a groupware for collaborative editing consists of isolated local networks. This system provides group-based network service which allows direct connections between the users of the group. Multi-synchronous semantic wiki [8] is another approach which allows direct connections between sites who know one another i.e. friend to friend network. The multi-synchronous semantic wiki collaboration model hides the social relations among sites participating in the network. However, by analyzing the causal history we will be able to reveal these relations and reconstruct the social network graph. These relations will be represented semantically and we will be able to deduce them using a semantic reasoner. Such approach can enrich the collaboration among the sites with new services, while at the same time preserving the sites' privacy, since we have a local vision of the network, and we do not rely on a service provider to maintain the social network. Next sections will explain our contribution to multi-synchronous semantic wiki to reveal the social relations.