There are some very serious felony laws in the United States that can be applied to anyone who has in there control magnetic stripe/credit card equipment. The law is written so that even if it was legitimate use the burden would be put on you to prove a legal use. I would not even go anywhere near this area. This is not a game you will GO DIRECT TO JAIL

fyi: here is just a taste from Arizona never mind the other Federal laws that apply:

13-2106. Possession of machinery, plate or other contrivance or incomplete credit card; classification

A. A person commits possession of machinery, plate or other contrivance or incomplete credit card if such person:

1. Possesses an incomplete credit card with intent to complete it without the express consent of the issuer.

2. Possesses, with intent to defraud and with knowledge of its character, any machinery, plate or any other contrivance designed to reproduce an instrument or device purporting to be the credit card of an issuer who has not consented to the preparation of such credit card.

B. Possession of machinery, plate or other contrivance or incomplete credit card in subsection A, paragraph 1 is a class 1 misdemeanor and a class 6 felony in subsection A, paragraph 2.