North Korea is trying to crack down on an insidious form of espionage; smuggling official (but unclassified) government documents out of the country. Many North Koreans are willing to risk prison or execution by smuggling out government documents and publications. Foreign intelligence agencies and journalists pay well for these innocuous items. While it’s not impossible for foreign embassy staff to obtain these documents, it is illegal for foreigners to possess them and diplomatic personnel are watched constantly.
It’s been found that the easiest way to get the documents out is to arrange (via payments and bribes) to have them hidden among the items regularly exported to China. A lot of stuff goes to China each day, because China is North Korea’s main trading partner. All the raw materials and food items (especially fish) cannot be searched so there is a booming business is moving this stuff across the border to Chinese intelligence and Chinese brokers who will, for more fees (and at some risk to themselves) get documents out of the country for foreign journalists, intelligence agencies and anyone else willing to pay.
The documents include orders for state bureaucrats, training outlines for propaganda staff (North Koreans spend a lot of time getting lectured by government instructors) and all manner of publications. Taken together these documents provide details about North Korean culture, attitudes and the economy. That why foreign journalists and intelligence analysts will pay so much for this stuff.