China is marrying Big Brother to Big Data. Every citizen will be watched and their behaviour scored in the most ambitious and sophisticated system of social control in history. 

Leave No Dark Corner,  produced by Cecily Huang, Reported by Matthew Carney, Shot by Brant Cumming, airs on Foreign Correspondent at 8 pm Tuesday September 18 and 1.30 pm Friday September 21 on ABC TV and at 7.30 pm AEST on Saturday September 22 on the ABC News Channel; also on iview.