For the third time this year, Sen. Sherrod Brown (D-Ohio) has penned a letter appealing to Consumer Financial Protection Bureau director Richard Cordray to crack down on out-of-hand debt collectors. "We're just hearing more and more of these stories," the lawmaker noted. "These agencies are pretty aggressive." Brown wants Cordray to compel debt collectors to produce proof -- a signed contract, for example -- that a debt is owed; prohibit the sale of debts lacking such documentation; and block collectors from going after time-barred debts, among other restrictions. In addition to trying to collect on old debt, debt amounts that have been inflated, and debts that were not incurred by the targeted consumer, debt collection firms are pursuing credit card debt that often consists of predatory fees and interest but no unpaid principal. Moreover, when foreclosed homes fail to generate enough money at sheriff's sale to cover the mortgage balance, the difference is being offered up as debt available for purchase by debt collectors. "There's been a yawning absence of enforcement or regulation of debt collectors for a long time," laments Margot Saunders of the National Consumer Law Center. "Sen. Brown is rattling the cages."