Online credit card payments can hardly be authenticated, as anyone who
knows the credit card number could just fill out an online payment form
and pay. So there really is no way for the online store to verify that
the person who makes the order is really the owner of the credit card.
This is a huge problem on the Internet right now as far as I know.

If you want to buy some hardware from another country, you will mostly
have to somehow convince them that you own the credit card. They will
ask you to fax them for example the front and the back of your credit
card with you ID or passport next to it. That is really troublesome way
to authenticate. The best on line authentication I have seen is Paypal
and Ebay, which requires the user to check their bank account statement
for a secret very small payment amount or/and receive a code as a
physical mail. To verify that they own the credit card or/and to verify
their physical address. Those authentication practices cost time and
money and are really not efficient.

I found the solution that Google is probably waiting to implement next
month when it is launched globally for the first time, as far as I
know. It is the 3-D Secure credit card payment authentication system
for all credit cards Visa/Mastercard/JBC and later Visa Electron and
some other..

It will require the internationnal user to be connected with their
bank, for example with their Internet bank system. It will enable
somehow, probably with a digital signature or some kind of code which
Google will give you, which you have to copy and past at your Internet
bank connection, it will answer you with the authentication code, which
you past back to Google. Then Google will have authenticated your credit
card, it will mean they are now sure you are the one who owns the card,
thus you will be able to pay for as much video at Google Video Store as
you want. So this is a very cheap and very reliable way it seems for
future online services like Google Video Store to accept online credit
card payments finally in a very secure way!

http://partnernetwork.visa.com/pf/3dsec/testing.jsp

This seems to be the real solution for online payments that the credit
card companies have finally come up with. And it will probably quickly
be adopted by many online stores, especially usefull for online digital
services where no physical product is shipped like Google Video Store.