In this paper we discuss new challenges to design with the increasing mass availability of data to various communities through what we term 'collective sensor networks'. We review new projects that we believe will have considerable impact for HCI and CSCW and consider their practical implications. We explore design challenges for future-oriented and sustainable communities that are built around sharing and integrating data from various sources. We are interested especially in how these projects involve and envision interaction between different actors and across different scales. We also wish, through drawing on notions of fiction in literature, to explore the practical possibilities of connecting new kinds of data through a network for the creation of new communities and a series of implications for interaction and interface design that deal with these heterogeneous actors and various scales. Copyright the author(s) and CHISIG.