President Xi Jinping has urged public bodies to “defend information security” after a hacker offered to sell stolen data of one billion Chinese citizens. Cyber-security experts have verified that at least some of a small sample of the data offered is real. In an advert on a criminal forum, later removed, the user said the data was stolen from Shanghai National Police. The 23 terabytes of data is thought to be the largest ever sale of data on record and was being offered for $200,000. What is the worst that can happen with the stolen data ?

