In 2013, a 29-year-old US government intelligence employee came to Hong Kong to secretly meet with journalists. Edward Snowden leaked tens of thousands of top-secret documents showing that his employer, the National Security Agency (NSA), was illegally seizing the private records of billions of individuals who had not been suspected of any wrongdoing. Becoming one of the world’s most polarising whistle-blowers, Snowden revealed that the US was spying on countries and leaders, worked together…