If you live in the US, you might know about these cars. You rarely see them around, but when you do, you can see the large cameras mounted to the car to record street video.
Usually you won't see this many cars, but here is a picture of a Google Street View Car Fleet getting ready to set out and (attempt) to map the world.
Here is a question to all of you: What would you do if you spotted one of these cars going along the streets, and even into your neighborhood? Would you observe, follow it?