While I agree that the street-level cameras should urgently be taken care of, don't underestimate what a stationary aerial drone can do over a couple of hours.

Listen to Radiolab's Eye in the Sky episode. Think of the possibilities that have opened up because of drone tech in the 10 years since it first aired (and the 20 years since the tech was used in Iraq). It's truly frightening what these drones will be able to accomplish once they are in place.

I don't think sending a couple drones to canvas a city grid from the sky would count as less useful. In fact, it'd be a lot faster than strapping a camera to a truck/car. Really depends how they are used. But worst case scenario, both drones and fixed cameras work in conjunction, which they obviously would.