China is doing it at MUCH larger scale and a lot more intrusive. Everything on the internet is tracked and filtered, cameras everywhere. Chinese government can pinpoint location of any of it's 1.3 bln citizens.
China doesn't have near the surveillance infrastructure that the US government does outside of China.
The simple fact that China has more citizens to surveil does not mean China is conducting surveillance on a larger scale.
https://addons.mozilla.org/en-US/firefox/addon/hn-friends/
https://chrome.google.com/webstore/detail/hn-friends/ffgfcbf...