Several years ago plans to destroy the remaining legal stocks of the virus that causes smallpox a disease supposedly now eradicated were dropped on advice from America's intelligence services, among others, that North Korea and other countries were secretly experimenting with the stuff.

ECONOMIST: Biological weapons

Pretty ordinary stuff in the world of social media, but revolutionary for North Korea, a country with intricate rules to stage manage the flow of images and information both inside and beyond its borders.

NPR: Tweets, Pics Give Real-Time Peek Into North Korea