In Yakuza Judgement, a detective agency often uses a quad-copter drone with a camera providing a live feed in the bustling city in Japan. One use they have for it (which is obviously problematic) is to snoop in buildings through windows.
But that usage aside, another way it's used is to remotely monitor one of their agents and provide back-up, without having to actually be there on the scene. Is using a drone like this legal? So long as you're not disturbing the peace and being dangerous, of course.
Since the game takes place in Japan (mainly Tokyo/Yokohama), my question is mainly directed there, but I'm also curious about what the law says about it in the United States, or other countries.
I am in particular reminded of the stories I've heard of disabled students using robots with cameras in order to attend school, which leads me to believe that this must be legal to a certain extent.