Medical database privacy

In August 2016, the Australian government released to the public a data set containing the medical billing history of nearly three million persons: every procedure they had undergone or prescription they had received. Needless to say, their names and all other identifying features had been redacted. Nevertheless, within a few weeks a group of researchers at the University of Melbourne discovered how easy it was to re-identify the individuals in this ostensibly anonymous data set and extract their medical history. The researchers did this by using information readily available on the internet. The media coverage of their paper bordered on hysteria; the Australian government was forced to remove the dataset from its website—but not before it had been downloaded nearly 1,500 times.