Go to the Telegraph and look for the article that shows where the photographer was when he took the photo. It's a few miles down the road, in a place where there is a slight gap between trees so you can get a distant look at the chateaux. He used a telescopic lens at God knows what magnification to get grainy pictures.
If some pervert from miles away uses a telescope to spy on your daughter changing clothes, I bet you wouldn't feel the same way about it.