StarBlazer: I agree with the OP on this. My concern is loss/theft of my wallet. In the hours it takes for you to become aware that you no longer have your credit card, how many tap n' go transactions under $80 could be performed? Sure shops will have CCTV, but the chances are the perps will be out of area on a spending spree. Even then we presume the police have the time to follow up on these grainy pixelated images. It doesn't have to be high value items, just something that could be offloaded easily through TradeMe or Cash Converters.
How does this differ to the past ~20 years where somebody could simply walk into a store, buy groceries, and sign your signature because it's on the back of your card?
How does it differ to somebody using your card online to buy goods or services where no other details are required apart from your credit card number?