Governments around the world are posting many thousands of their datasets on online portals. A major purpose of releasing this data is to drive innovation through Big Data analysis, as well as to promote government transparency and accountability. This article considers the benefits and risks of releasing government data as open data, and identifies the challenges the Australian government faces in releasing its data into the public domain. The Australian government has ambitious aims to release greater amounts of its data to the public. However, it is likely this task will prove difficult due to uncertainties surrounding the reliability of de-identification and the requirements of privacy law, as well as a public service culture which is yet to fully embrace the open data movement.