In Prosecutors, Debt Collectors Find a Partner - NYTimes.com:
So you get a "Pay up or go to jail letter,"and...
"They bear the seal and signature of the local district attorney’s office. But there is a catch: the letters are from debt-collection companies, which the prosecutors allow to use their letterhead. In return, the companies try to collect not only the unpaid check, but also high fees from debtors for a class on budgeting and financial responsibility, some of which goes back to the district attorneys’ offices."