While China has enlisted its internet giants — such as Weibo — in its system of social control and surveillance for years, a new "cyber security law" will come into effect on Thursday that expands and formalizes this role for tech companies, with implications for non-Chinese companies doing business in China.
The law — passed last November by the rubberstamp Chinese parliament — requires internet firms to surveil and retain all user communications, while implementing penalties for abuse of this information.
Until now, China's data industry has had no overarching data protection framework, being governed instead by loosely defined laws.
However, overseas critics say the new law threatens to shut foreign technology companies out of sectors the country deems "critical", and includes contentious requirements for security reviews and data stored on servers in China.
China to implement cyber security law from Thursday