From Neighborhood Retail Alliance:
When the folks voted to install Mike Bloomberg as their mayor-and did it a second time-the prevailing wisdom was that, owing to the mayor's vast fortune, the public could count on a corruption-free mayoralty. What was not taken into consideration, was the Bloomberg old boys network that gave Dan Doctoroff and the Related Companies to NYC. As a result of this, we were able to bear witness to a whole series of sweetheart no-bid deals that left the city less well off than it should have been.
No-bid deals similar to ones at the Department of Education (years later you find out the school is contaminated).
There was also some shady bidding for a project to clean up the Staten Island landfill.
In the era of open government there are still a lot of deals happening behind closed doors.