If you have not signed or agreed to be responsible or used the cards, you would not be legally obligated to pay accounts in someone else's naem. However, if you knew someone had obtained accounts in your name and said nothing for 4 years, while those cards were being used and bills run up, a court might very well hold you responsible.
A person can always file their own bankruptcy, however this is very much a BAD IDEA. Bankruptcy is a difficult thing to do properly, and you would have no way of knowing what the dangerous areas are.
Please note that I do not practice in your state and that the above is not intended as legal advice.