We're building a small device with a 'cheap' lidar sensor. It can see right across the street, through a window, and show people walking around inside their living room. We have a process to remove this data before any human sees it. However a lot of intelligence can be collected from the ground these days; and a lot of secure sites are aware of exposing too much to the sky. I'd be more worried about that Cessna Caravan doing lazy racetracks over my site than a drone buzzing around.