RFID, WTF?
RFID stands for Radio Frequency Identification but who really gives a crap.
All you need to know is that it's the reason you shouldn't steal CDs or DVDs.
Without the sensors I would be more inclined to... uh, nevermind.
Since swiping credit cards through a terminal is so '90's, the credit
card companies devised a way to make it 'easier'
for people to augment their debt. When you use a credit card with RFID, instead
of swiping your card you just hold it up to the machine and after a
second it grabs your card number and expiration date through the air
and processes the transaction without a signature.
Doesn't sound so scary, does it? But remember, these companies are not concerned
with your security as much as you would hope. If this were the case, we'd be
using PIN(-only)-based credit cards where some jackass can't use your lost
card to fill up his SUV with $80 in gas. Instead, we still use signatures which
are as obsolete of a security measure as putting a spare key under your doormat.
(I will admit
that I have used it a few times and while it is kind of cool, the more accurate
way to describe it is gimicky and unnecessarily unsecure.) It even works just
by waving my wallet without removing the card. As easy as it is for the machine
to pull your information off the card without any physical contact, someone
with some smarts and low morals can just as easily brush
past your wallet and do the same without you ever realizing it. Since RFID
is the next big thing for payment methods, its only going to become more of a
problem as more people learn how to hack it.

What's in Your Wallet?
Despite all the money put into marketing these new breed of credit
cards, they sure keep mum about whether your card actually has an RFID chip inside.
I recently traded my Sony Card that I signed up for because of the free $100
credit for the Chase
Freedom (Cash) card because of the cashback. The website description as well
as the documentation I received with the card makes no mention of any contactless
technology. I would have been none the wiser if it wasn't for a suggestive logo
that made me do some googling only to find out that it does have a chip
in it.
Chip On Your Shoulder In Your Pants
If you are unsure whether your credit card(s) have an RFID chip in them, do a
Google search with the name of the card and "rfid." Now that you are
sure that your card is not just plastic, the next step is finding where
the chip actually is so you can destroy it. If you hold it up to the light and
look at the glare, you should see an indentation somewhere, possibly underneath
or near a logo indicating some sort of speedy checkout technology.
On my card, I found it to be located under the broadcasting logo on the back
of the card rather than under the chip design on the front. Although it is faint
in the picture, its actually much easier to see with your own eyes than to capture
on camera.
Safe At Last
Once you know where the chip is, you simply drill a hole in it with something
like a dremel or drill. It's as simple as that!