Can a cl-action stop American Express from lowering credit limit?

I have been reading and hearing about American Express lowering customers’ credit limit. Well they just did it to me. Isn’t this an intentional act to defame a person's financial character? If someone is trying to take advantage of the real estate market to buy at the lower prices now; they cannot do so. Amex wants to get a piece of the $700B pie, but yet take drastic measures to squeeze the consumers. Congress should really look into this!! The "Universal Default Law" which I believe was strongly supported by our Vice-President elect should be repealed in these financial times. It's adding salt to the wound. These financial corporations find themselves in trouble because of moral deficiencies and financial greed, looking to the taxpayers for bailout and penalizing the same taxpayers at the same time. What is wrong with this picture? Are they biting the hands that are feeding them?