That's like saying there need to be a policeman for each citizen. Things don't work like that. The system isn't in one to one relationships.
Anyway it's a theory I heard somewhere I make no claims about it's validity. However I do believe there is something to it which explains why North Korea is so gong ho about controlling information (and being so successful at it)
There is a reason why they weld the radio station to one frequency and why the the US is trying to smuggle radios over the border.