Yeah... a real pain and a growing problem.
First time I went to Argentina, I contacted the CC company to inform them I was traveling and not to shut down purchases in Argentina. So when I got back to the US I had a call on my answering machine to contact CC services ASAP. As I was going through MIA leaving the country, I bought a book in the airport book store. The cashier told me her card swipe was down and she needed to process it the old fashioned way.... roll the card and leave the receipt with the number..... Seems that someone in the store swiped the receipts and my number was used in California to buy $1500+ worth of electronics. I went through the charges on the card since I left till I returned and the CC company ate the charges I didn't make and issued a new card.
My wife recently got a new card due to the TARGET scandal.
It always pays to check your bill....item by item. If you get a fraudulent charge and pay it.... then they hit you again for a larger fraudulent charge, it's hard to dispute the second one since you paid the first one.
The new cards coming out now are proximity cards and can be read by the sniffers when they are simply close and the cards are still in your wallet in your pocket. Companies are selling RF screening inserts and wallets to prevent that.