I've been thinking about this earlier.
There's been a bunch of girls trampled and injured, with 13 hospitalized, when they tried to rush in to get to see a free Justin Bieber concert. The reason why they were in such a frenzy to get there was because his lyrics speak personally to the listener.
So I had this idea that if you were some mad dictator, you could hire a popstar to spread propaganda through your country's youth to help prevent rebellion.