This deserves an award or something. Although generally, it might be risky. Like, thieves and stuff. They would know when a door is locked and all that. Well I guess that they should just design it like the usual design so there wouldn't be any problem. I guess this is nice because when we're about to leave the house, right? By just looking at it, we would know whether we've locked the door or not. I guess this is just brilliant.