Did you really think your credit card company was doing you a favor because they are nice people? You'll find out the hard way when you send you a Form "1099-C," which counts all of the debt your friendly credit card company forgave as income you never earned, but now may be liable to pay taxes on.
Had you filed bankruptcy before they forgave the debt, then there would be no chance of any tax liability for you. Debts canceled by a bankruptcy court are never counted as taxable income. Debts forgiven by credit card companies can be counted as taxable income.
I recommend reading the article below for a valuable explanation of how you can protect yourself from forgiven debt published in the Pittsburgh Tribune.