From AFP, Google is concerned about the latest Vietnamese government regulations involving the internet. New regulations would require internet retailers to install software to track user activities. Eventually this could lead to specific websites being blocked by the Vietnamese government.
Read more here -> Google troubed by new Internet rules in Vietnam – AFP
I guess I do not want to state the obvious here but for the last 6 years, certain websites in Vietnam have ALREADY been blocked. Yahoo Geocities sites were blocked in the past; Facebook with FPT and EVN are currently blocked; many human right’s sites are already blocked. Even my blog is blocked with certain ISPs. No news here…
Furthermore, the government can already track the online activities of internet users. To register for an internet line, you either have to present your Vietnamese ID or passport if you are a foreigner.
I am guessing the new regulations are just trying to stop people from using OpenVPN, OpenDNS or Google Public DNS. That is just a guess of course…
Regarding the facebook block, there is a new theory behind it, if you can read Vietnamese check it here
http://s2facebook.com/forum/showthread.php?23022-Ch%E1%BA%B7n-Facebook-t%E1%BA%A1i-Vi%E1%BB%87t-Nam-l%C3%A0-h%C3%A0nh-vi-c%E1%BA%A1nh-tranh-kh%C3%B4ng-l%C3%A0nh-m%E1%BA%A1nh
According to this, it has nothing to do with politics but more about economic reasons (these isp providers are launching their new social networks website, so it’s a fast and dirty way to get all Vietnamese users)