Correct. Generally speaking, it's the merchant's responsiblity to properly authenticate the customer. For online transactions, that's one reason that three digit code is on the back of your card. I've heard, but don't know for certain, that transaction feels are lower when the three digit code is required on online transations.
Originally Posted By: dparm
Originally Posted By: Quattro Pete
Originally Posted By: eljefino
Yes because the clerk is supposed to check signatures between customer and card.
What if it's an online transaction and no signature?
The credit card transaction fee is typically higher for this since fraud is a bit easier. Either way, it's almost always the merchant that eats it unless they're out of business.
For the record, Amex's dispute process is the best by a mile. They almost always side with the cardholder.