I think the Google truck is slightly invasive. Only slightly. But I love street view. Saves me an absolute stack of time on a regular basis...
I'm just looking at something in Charles Street Lilyfield, and 1 street East is Hubert St. There's a lane between these streets, and The Google Street View Truck went down the lane, and because the camera is mounted at say 1.8m to 2.0m, you can see over the fences and straight into peoples back yards!