I am a guest moderator here, I do not work for Alibaba and have no affiliation with them except that I moderate this forum. My opinions are mine alone and not those of Alibaba.
Sorry I'm having some problems understanding your English, this makes very little sense to me:
"what is your action if Alibaba has been scammed as one as their member". If you are asking what I can do if someone gets scammed, nothing really, except sometimes provide advice and information. Most of what I try to do is prevention. You would have to contact Alibaba if you want to know what they can do:
http://www.alibaba.com/trade/servlet/page/static/help/contact_us_answer or alibaba@alibaba-inc.com
It is often complicated for someone not in China to check up on a Chinese company, this is pretty much a fact. There are however plenty of companies and professionals here that provide these kinds of due diligence services for a fee, so it is not impossible. Certain scammers are easily recognised and with those I will state my opinion as my time allows. But with China, legitimate companies sometimes act in very strange ways by "western" standards, they often use Western Union to receive payments, they like to use free email addresses and some have poorly designed websites with very strange domain registrations. And this is among those that I know are legitimate, which is why I'm afraid to say much about any of them. There are plenty of companies outside of China where I can't provide much useful information either. It's of course true there are scammers in China just as in most other countries, you need to be as careful there as anywhere else, even more so if you are not experienced in dealing with China.
I hope this explanation was a bit more to your satisfaction? I assure you this is all there is to it, I am not part of any conspiracy here. But I like the tinfoil hat attitude