Over the last several months, 22,741 New Yorkers contacted the city’s Department of Sanitation and arranged for the pickup of refrigerators, air-conditioners and freezers. In more than 11,000 instances, the machines vanished before sanitation workers arrived in their white trucks to pick them up.

Who, then, is stealing the household appliances of New York City?

Perhaps it is not the most pressing question facing city authorities, but it is something of a mystery nonetheless. The appliances did not develop legs and walk away, and they did not simply disappear.

Scavengers, to be sure, abound in New York, especially during tough economic times. But the sheer magnitude of the thefts  11,528 appliances, to be precise  over a relatively brief period suggests to some in city government and the recycling industry that a more organized enterprise may be at work as well.

Deepening the mystery, these were neither the latest Sub Zero behemoths, sleek Bosch nor stylish retro Smeg refrigerators. They were garbage, quite literally  discarded appliances left at the curb for pickup by the Sanitation Department.