Not long ago, ABC News ran a story showing how easy it was to collect account numbers and Personal Identification Numbers (PINs) from unsuspecting consumers. In their experiment, they set up a sign next to a banking ATM that offered to “clean” magnetic strip on people’s cards as a courtesy to their customers. The sign had a magnetic card reader attached to it so that people could swipe their cards to have them “magically” cleaned.

And how many people fell for it? You’d be surprised. In their experiment, more than half of people used special card cleaner before using it in ATM. Fortunately, this was only an experiment and no account information was actually transferred from “fake” cleaning machine.

First and foremost you must understand that using your credit card after you’ve received this notification results in your automatic “agreement” to new terms in notice. To prevent these new terms from affecting your account you must stop using that credit card immediately or by date given in notification statement.

The most common modifications to credit card agreements include new APR’s (annual percentage rates), new fees and/or changes to existing fees, or a change to grace period on your account. The grace period is number of days during which any credit used for purchases may be repaid in full without incurring a finance charge.

Not knowing or not keeping track of dollar amount limit on your card is another trap you should avoid. Credit card issuers will allow you to charge a small amount over limit set on your account. However, don’t be surprised when you get hit with an “over limit fee”, usually around $35.00 or higher, on your next statement. Also, be prepared for your APR to be increased if you go over your credit limit.