Well this is a disturbing trend. Mailmen in the Bronx have been getting robbed over the past year—for their keys. Since January 2010 at least four mailmen have been ambushed and robbed of the keys to the buildings on their routes (and occasionally some of the mail). The NYPD has yet to connect any crimes to the stolen keys.
The first key-napping occurred January 8, 2010, and there have been at least two more since December 2, 2010. The most recent robbery was February 22. And in at least one of the incidents the thief pulling a gun on the mailcarrier in question.
What exactly the crooks want with all those keys is an open question (key party?) But we gotta say, stealing keys to buildings from a mailcarrier is actually not the stupidest scheme we've ever heard? Those locks aren't that likely to be changed in a timely manner, and the keys can provide crooks with easy access to not just buildings but also mailboxes (which can have valuables and valuable information in them). Which is why many buildings keep their mailboxes in the foyer between the front door and another locked door with a different key.