Originally Posted by ungratefulninja

I used to work for Chase and maybe they changed their policies but at the time they actively engaged in repricing. I remember a guy that had $45,000 charged on his credit card at a decent interest rate and always paid it on time. His credit score went down from something that didn't involve Chase whatsoever, but they jacked his rate up to like 30% on his existing balance. Basically fucked him over.

from http://www.pbs.org/wgbh/pages/frontl.../credit/eight/

If you've ever looked at the return address on your statement, you may notice your credit card issuer is located in a state such as South Dakota or Delaware. That's because these are the states that have either weak or no "usury laws" meaning there is no cap on the interest rate that is charged. The federal government once had national usury laws that set a cap on the amount of interest that could be charged on a loan. But after the Great Depression, it repealed them and some states put no new usury laws in place. That's why Citibank, the issuer of Mastercard, moved to South Dakota, which has no cap on interest rates.