Comparing what the NSA does to what China does is like comparing the treatment of women in the US and Saudi Arabia
Why do you have so much certainty? What evidence can you provide that they use or currently plan to use these techniques domestically for widespread tracking?
No matter it's many faults the US is still a democracy with checks and balances.
B) this is not an excuse for the consistent course towards militaristic, authoritarian state fueled by fear.
EDIT: Sourced claim.
[0] https://mobile.abc.net.au/news/2018-11-01/satellite-images-e...
https://addons.mozilla.org/en-US/firefox/addon/hn-friends/
https://chrome.google.com/webstore/detail/hn-friends/ffgfcbf...
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.
While I agree with what you're saying, it makes sense that we'd be getting this information only just now - after there has been enough time for 1) data scientists and the like to become prevalent/cheap enough for government contracting and 2) enough time to build working applications on top of all that data.
[0]: https://en.wikipedia.org/wiki/Gait_analysis [1]: https://youtu.be/JASUsVY5YJ8?t=278