> Sell personal details like credit card numbers or the SSN to a criminal syndicate.
That kind of ticky-tack stuff seems more like the work of organized crime ring than a national government of a state like China. Anyway, that stuff is subject to much more prosaic risks, like your being at the mercy of your dentist's office's online security set-up.
I don't think people need a reminder of that. The US government also isn't a monolith, as J. Edgar Hoover's abuse of power as the head of the FBI reminds us.
I'm not "idealizing" China; I just think that, realistically, credit card fraud is a weird tack for a large world power to take. If we're talking about rogue individuals, OK, but you probably need a local fence, complicating things, and you could make the same argument about just about any entity you interact with. I'd say the risk of a call center employee stealing your SSN to commit fraud is higher than someone in the MSS doing the same.
DDoS the whole infrastructure. They have done that to GitHub before by hijacking traffic to Baidu. With millions of phones in the US under their control it’s fairly easy to overwhelm any website (Mercedes comes to mind in recent news) they don’t like or even cripple the whole national wireless network.
Also even if you are not of direct interest to China, what about your friends and colleagues? They can use you as a tool to get to those that you have direct communication with.
> What can China do to someone a US citizen, living in the US, using a Huawei phone?
What can the US do to someone who's not a citizen, living outside the US, with access to their communications? It's not difficult to find an answer to this. China would do the same to you and you won't be able to fight against it because you're not a citizen of China.
US get extradite people from all around the world quite easily. On the other hand, extraditing a US citizen to another country is very difficult as US is more likely to block such efforts. For this reason it might be safer for US citizens to be listened to by Chinese government instead of US. It's a tradeoff you need to make and it depends on your circumstances of course.
What can China do to someone a US citizen, living in the US, using a Huawei phone? Even if all telephone calls are monitored?
What can the US do to someone in the same situation?
Yes, others are in different circumstances and would make a different choice. Best of course would be to have no mass surveillance system.