It seems like absolute overkill. But the truth is if you positioned your camera and it showed a public area, if somebody complained to the ICO you could get fined for not registering. There's also a fee to register. So from the point of view of the person putting up the camera, it'll probably...
You also have to make sure that your camera isn't facing any public areas or neighbours property or the camera can cease to be for private use and technically by law has to be registered with the ICO.