Are banks required to refund overdraft fees? This guy was told that his bank would not refund the fees. This woman was also told that she was responsible for overdraft fees. This states that banks are not required to refund overdraft fees and this class action lawsuit specifically mentions people who have suffered damages in the amount of overdraft charges. So, as far as I can tell, banks are not required to refund overdraft charges.
Regarding liability for the actual charges, I have seen multiple articles like this quoting $50 for credit cards and $50 (within two days) or $500 (2-60 days) for debit cards. The FTC website, however, says that you are not liable when your credit card or debit card number is stolen (for debit cards you have to report the charges with.