I asked this question before and did not get satisfactory answers.

Can Vietnamese citizens in Vietnam open investment accounts abroad at ETrade, Ameritrade, Scottrade, and buy stocks?

duhhhhhhhhhhhhhhhhh
some VC officials already done so

Not with Scottrade. They got a Chinese language service, but you still need SSN for tax reporting to IRS. And all branches are US based as far as i know. But they might be able to get a brokerage account with Citibank maybe, or one of the aussies banks to access stocks listed on US market exchange. Lots of foreign companies listed as ADRs on US exchange, maybe some US companies listed on Saigon exchange?

You've made your post worthless by using "Saigon Exchange". There is no such Exchange with that name.

Seriously, can ordinary Vietnamese citizens with a few thousands US dollars open an investment account abroad and purchase or sell stocks internationally?

I heard that you are not allowed to transfer money abroad from Vietnam unless it is urgent matter like for schooling, etc.