The following article from The Economist China’s aversion to encryption technologies — which would make mass surveillance more difficult — makes the country’s networks vulnerable to foreign spying:

Weak security is the rule, not the excep­tion, in digital services for the Chinese public. Email and social media must all fa­cilitate state access, as must industrial net­ works used to run factories and offices, even if the extent to which the government uses that access varies. In August it banned the most up ­to ­date version of a protocol used to encrypt web traffic, known as TLS, from the Chinese internet, because it makes online surveillance harder.

(…) The government has responded by promoting programs for companies to improve customer­ data pro­tection, even as it simultaneously enforces weakness in the security of all systems. But as long as the government demands access to data on Chinese people, those data can never be robustly protected.