The great thing about cities, though (at least from this perspective; on the other hand, this same blessing is a total curse when it comes to stargazing), is that they have plentiful light even after the sun is down. Traffic lights, street lamps, lights shining through windows, car headlights...the list goes on and on. So even though the almost total absence of natural light sources, the city is nevertheless illuminated throughout the night.
This does tend to give a bit of a soft red "glow" to photographs taken in these circumstances, but it is in an atmospheric way that I think lends a bit of drama to the pictures.