In the last few years, there has been a rise in crime involving people going around with RFID readers and stealing people's credit card information without the victims even realizing it. Having an RFID-blocking wallet is the simplest and most effective measure to prevent this from happening to you.
RFID (Radio Frequency ID) is a technology that allows a reader to get an identification from a passive device by reading the device-specific response to a band of radio frequencies. Just by being near the reader, a device with an RFID tag or chip can be read wirelessly and instantly. The advantage of this is convenience. For example, you can now pay the bus fare by tapping a pre-loaded card on an RFID reader when you step on the bus.
Many credit cards now have the ability to pay by tapping on an RFID reader -- no swiping or inserting necessary. The disadvantage of this is how conveniently easy it is for thieves to get your credit card information (or more). And worse, they can do it right in front of you and you won't even realize it!
