This paper discusses how born-digital cultural material can be opened up for research. We focus in particular on the grey area between private mobile phone data and its publication and use for research and beyond. We report on the results of the `Empowering Data Citizens’ (EDC) project, which is a collaboration between King’s College London and the Open Data Institute. The work builds on the project Our Data Ourselves (http://big-social-data.net/), which studies the content we generate on our mobile devices, what we call big social data (BSD), and explores the possibilities of its ethical storage.