These people are most likely Americans, of Chinese descent. They are probably also 2nd or 3rd generation Americans, like yourself. They went to American schools and universities. They speak perfect English. They vote. They are patriotic. And they pay their taxes.
These people have no connection to the China government. They probably don't have any more close relatives that even live in China. So their connection to their ancestral home lands have been severed. They are by definition, Americans.
Now, yes, there may be some people in Silicon Valley, who are Chinese nationals, and who are working with an H-1B visa. I don't know the numbers breakdown.
But, I think you need to make a distinction between the two types.
I looked at this a couple weeks ago. The numbers depend on how you measure 'user' and 'location'.
Silicon Valley: 5% - 14%;
US: 32% - 56% (including SV);
Europe: 28% - 35%;
Canada/Australia/New Zealand: 7% - 8%;
India: 2% - 7%;
China: 0.5% - 3% (including Hong Kong). From European countries, the UK is 5-8% (of the HN total), Germany is 4-7%, France is 1-3%. The Dutch and Swiss are (stereotypically) stable at 2% and 1% respectively.
These ranges include measures like logged-in-ness. If you only look at total users then SV is less than 10%, and the US comes out less than 45%—or even as low as a third, depending on what's specifically measured.
