I found this map on Pennylicious (a terrific blog about money). It's a really interesting look at where the top 10 credit card issuers are chartered - states with the weakest limits on interest rates. 5 of the states don't even have limits. And even if you live in a state that has a strict limit on interest rates, if the bank you use is not based in that state, the limit does not affect that company. National banks only have to follow the limits of the state in which they are chartered. Sneaky!