Has anyone use the virtual credit account number from Citi card?

What is virtual account numbers? According to Citicard website, it is a free security tool that allow you to generate a randome credit card number that's good for one merchant only and make it virtually impossible for anyone to steal your account number when you shop online. You will never have to give out your real credit card number online with this Virtual Account numbers.

It is actually quite easy to set it up. You ...