Digital technology has become increasingly pervasive in China, with the government planning to cover the entire nation with surveillance cameras capable to gather personal information in real time.

Beijing promised to build the world’s largest surveillance system, and in the next three years 400 million new cameras will be installed, along with the 170 million already in use. These cameras will also contain the most sophisticate technology available: the surveillance system’s AI can read faces, age, gender and ethnicity.

The BBC’s John Sudworth meet the Guangdong’s police to demonstrate if China’s Big Brother is really effective. The surveillance system took 7 minutes to discover Sudworth in the city centre and to send the alarm to police officers.

“Citizens has nothing to fear”, said a policewomen to Sudworth, explaining they “will only extract their data when they need our help”. Although not everyone is convinced by the surveillance system. Ji Feng, a poet and government critic, thinks the surveillance on dissidents may intensify.