Please read this Deal Book article by Jessica Silver-Greenberg. Here's a bit of it:
In the netherworld of consumer debt, there are zombies: bills that cannot be killed even by declaring personal bankruptcy. Tens of thousands of Americans who went through bankruptcy are still haunted by debts long after — sometimes as long as a decade after — federal judges have extinguished the bills in court. The problem, state and federal officials suspect, is that some of the nation’s biggest banks ignore bankruptcy court discharges, which render the debts void. Paying no heed to the courts, the banks keep the debts alive on credit reports, essentially forcing borrowers to make payments on bills that they do not legally owe.
HT to Ted Mermin.