The web-site data.gov.uk (the UK’s counterpart to the US’s data.gov site) was launched in January 2010. The site proclaims that “transparency is at the heart of this Government” and that “data.gov.uk is home to national & local data for free re-use.” As part of an assignment for a masters-level course on Data Security at the University of Oxford, 18 part-time post-graduate students were asked to give consideration to the benefits and drawbacks of releasing public data, with particular focus being given to data.gov.uk. In this paper we describe the findings of four of these students and show how the issues raised—both in isolation and when taken in combination—may be a cause for concern, both to those responsible for releasing such data and to those to whom the data pertains. The discussion is not intended to be a critique of data.gov.uk per se; rather, our hope is that this contribution may play a role in the wider debate pertaining to the issues surrounding the release of public data.