Many are fed up with unpaid salaries and substandard work conditions in other countries.
High-ranking authorities and members of the ruling Kim family routinely go to the city-state for medical treatment and luxury goods.
Defection often leads to severe punishment for extended family members, sources say.
Source familiar with plan says Pyongyang will use hackers to gather data without connecting citizens to global Internet
The decision is linked to sanctions against the reclusive nation for its nuclear development.
They are ditching their regular cell phones, as censors crack down on users who download foreign movies.
While allies decry senseless act of violence, Pyongyang hails 'righteous punishment.'
North Koreans are illegally crossing into China on the frozen Tumen River.
Deliveries arrive by ship and pipeline under the terms of favorable loans, sources say.