This live stream of our planet was activated on board of the International Space Station in April 2014 as an experiment to see how well cameras and similar equipment handle the harsh space environment. Just look how peaceful everything seems from up there.
If you don’t see anything it just means that the International Space Station is currently on the dark side of the planet. (the area with no sunlight).
To read more about the experiment visit the High Definition Earth Viewing page (link missing, sorry).