Unsecured claims held by credit card companies, and in particular by debt buyers, have kept bankruptcy judges and appellate courts busy recently. In the typical case, a credit card company or debt buyer files a claim which contains a summary listing the original creditor, the last four digits of the account number and the amount of the claim. The debtor objects on the basis that the claim is not supported by the documents establishing the claims and/or that the debtor does not know who the debt buyer is.