alt Hacker NewsThe lights are indeed outdoor, and cover most of my backyard. It's a neighborhood within a major metropolitan area, but the light doesn't bleed beyond my property lines.
As for the "why", the answer is security. If someone attempts to hide in my yard, they'll find it quite difficult to remain unseen.
Most of my neighbors have floodlights of their own (though mine are easily the brightest), and I've gotten no complaints in the years I've had them. If any of my neighbors voiced concerns about them, I would try to work with them to find a solution. I have to live next to them, so it only makes sense to stay on good terms.
My neighbour has a motion activated flood light. It's annoying. Not annoying enough to risk a feud by telling them though. It also completely ruins any natural habitat for nocturnal animals.
The whole concept of permanently lighting your garden is crazy! Where do you live that you're so worried about people hiding in your yard? Could you not solve that with cameras and an infra-red floodlight?