Online Social Networks (OSN) have already become an integral part of our daily online lives. We communicate with each other, organize events, play games, exchange information and files, and keep contact to our friends and relatives. We believe that OSNs will continue to grow in importance for our communication habits and social lives in general and become a general platform for online communication and information exchange.

Unfortunately, today's OSN platforms are mostly closed solutions, which are forcing their users to not only entrust all personal information to a single platform operator, but also to surrender copyrights. The personal data is then used e.g. for targeted advertisement or other forms of monetization with little or no control for users regarding how and what private information is used. The resulting consequences in terms of privacy and being locked-in by the OSN platform bother most users as control over one's data privacy is lost. Furthermore, users cannot connect and communicate freely with other platforms and services. Solutions proposed to address and mitigate these issues mainly proposed either alternative centralized OSN platforms themselves or rely on federated or completely decentralized architectures. All proposed alternatives have in common that users need to create a new user account within the new system, while seamless interaction with other OSN platforms is still not possible. The motivation for users to abandon one closed system for another closed solution is therefore limited.

To address these issues, SONIC proposes a different architectural paradigm for social networking by introducing a common API and protocol allowing exchange of social information between different OSN platforms, while addressing remotely hosted user accounts directly. This way, users can choose the OSN platform they prefer while staying seamlessly connected to all friends using other OSNs. Hence, it is rendered irrelevant whether a user's friends are using the same or a different OSN platform. The result is an Online Social Network Federation (OSNF) defined as a heterogeneous network of loosely coupled OSN platforms using a common set of protocols and data formats in order to allow seamless communication between different platforms.