At present, the rapid development of Online Social Networks (OSN) has strong influence on our global community'scommunication patterns. This primarily manifests in an exponentially increasing number of users of Social Network Services(SNS) such as Face book or Twitter. A fundamental problem accompanied by the utilization of OSNs is given by an insufficient guarantee of its users' informational self-determination and the dissemination of socially intolerable content. This results in severe shortcomings for both the possibility to customize privacy and security settings as well as the unsolicited centralized data acquisition and aggregation of profile information and personal content. In this paper we provide an analysis of requirements an OSN has to fulfill in order to guarantee compliance with its users' privacy and security demands. Furthermore, we present a novel decentralized multi-domain OSN design which complies with our requirements. This work significantly differs from existing approaches since it provides a technically mature mapping of real-life communication patterns to an OSN. Our concept represents the basis for a secure and privacy-enhanced OSN architecture which eliminates the problem of socially intolerable content dissemination.