Universidad Politecnica de Madrid
A continually increasing number of pictures and videos are shared in online social networks. Current sharing platforms however only offer limited options to de ne who has access to the content. Users may either share it with individuals or groups from their social graph, or make it available to the general public. Sharing content with users to which no social ties exist, even if they were physically close to the places where content was created and witnessed the same event, is however not supported by most existing platforms. The authors thus propose a novel approach to share content with such users based on so-called privacy bubbles.