I don't know that I can put this any better or crazier than the author of the source site has:
"One night In the fall of 1993, Harrod Blank had a dream in which he covered his car with cameras and then drove around and took pictures of people on the streets. The public, unaware that the cameras worked, reacted naturally. At the end of the dream, Harrod looked at pictures taken with the van of faces frozen in the moment of awe, pictures so powerful that the next morning he decided to attempt to build such a vehicle in reality."
Now take that dream, add 2000+ cameras, a bunch of wiring, and a flair for camera-based mosaic work and you get the camera van. I've got a ten spot that says this thing reeks of patchouli.
Related:
Highly Precise Art: BMW Art Car Videos [internal]