When Post Office subpostmasters up and down the country started to experience big shortfalls in their accounts, Post Office assumed they were stealing the money and prosecuted them. Hundred were given criminal convictions and many were sent to prison. Lives, marriages, reputations – all ruined. The shortfalls were in fact, a result of errors in the Post Office’s own IT system, known as Horizon. It was something the Post Office had always denied. For over twenty years, former subpostmaster Alan B...