Up until recently, I would have reminded you that the US government (admittedly unlike the Chinese government) has no legal authority to order anybody to do anything like that. Not only that, but if it asked, it'd be well advised to ask nicely, because it also has no legal authority to demand that anybody keep such a request secret. And no, evil as it is, the "National Security Letter" power doesn't in fact cover anything like that.

Now I'm not sure legality is on-topic any more.