The convictions of 39 Post Office workers were quashed on April 23 after the UK’s court of appeal heard that the crimes for which they’d been accused were in fact caused by the organisation’s Horizon IT system. The system, supplied by Japanese IT services provider Fujitsu, had erroneously registered cash shortfalls in Post Office branches, leading to hundreds of convictions of theft, fraud and false accounting between 2000 and 2014. The scandal is one of the biggest miscarriages of justice in British history. But the Post Office scandal reveals a wider issue. After decades of outsourcing IT systems, government officials no longer have control over technologies that can ruin people’s lives. To avoid future scandals, we need to take responsibility for the digital systems at the heart of governance – instead of just scapegoating IT firms and their products when things go wrong.