Sure sure they did signed it but you have to live there to know why they hardly have the ability to enforce it. If they do enforce it, the economy will be seriously crippled and many other unmentionable factors. People would consider you to be a fool if you live in Vietnam and buy legit stuffs. I do buy legit stuffs (mostly video games and a bit of anime) but in Vietnam even if they did signed that piece of paper, it wouldn't make much of a difference.
EDIT: If they do enforce it, more than half of the country's population will be arrested. It would be really "fun" to watch too.