Some work of ours from over at Public Space Mapping Group relating to surveillance.
I basically photographed and then mapped the locations and type of security camera, taking note of the cones of space visible to each camera. This a technique I hope to take further with the Dublin city centre map.
This is the camera map combined with other information; graffiti, areas of public drinking, open/closed facades; and areas where these conditions coincide, indicating under-utilised spaces.