As cultural heritage collections become available in digital form they can be used and transformed by publics outside of existing institutions. But what are the limits of these new forms of engagement? Even as we hack around structures of professional and institutional authority and create new pathways into collections, barriers remain. Lack of technical confidence, legal uncertainties, and the inherent politics of access can all inhibit broader participation. Drawing on examples from Trove and the National Archives of Australia, this presentation will explore the meaning of 'access' within the frame of open data. What do we need to see cultural heritage collections differently?