Because if we are recording our cat, that red light attracts him and destroys all intentionality of the video. Because if we are recording our children, a red light is simply disturbing. Because if we are recording our basketball team, that red light can be seen as a laser, a fact that can 1) disturb the players 2) attract the police directly to us.

And which law of what country doesn't allow to record videos and sounds of people without their permission? I mean, the n900 is sold in a lot of countries, right?