I read the other day that credit card companies are quietly changing the terms of the cardholders agreements.
They are changing their ability to drastically increase interest rates even in the event of a single late payment on an otherwise perfect payer.
They do not have to inform the customer, they just jack up the rate to 20, 25 or even 30%. So your rate could go from 9% to 25% if your payment is just one day late, just one time.
Credit card issuers are mostly banks, and banks are hurting from the subprime mortgage disaster, so they are looking to screw their customers as a way to shore up profits.