More and more, it makes BUSINESS SENSE for a local city/county/state to turn over collections to a COLLECTIONS agency.
You owe $20 that you didn't pay to the city. After 12-18 months the city would write it off as a loss anyways, to clear their books. If they send it to a collection agency, they write it off sooner, AND they just might get some money. Even if they give 20% on recovery, 80% of $20+ late fees is still better than the normal stick in the eye they get.