North Korean defectors must keep their identities and personal information confidential. If this information is leaked, family members who are living in the North face severe punishment or torture. Sadly, a defector who was working for the South Korean government on a 2-year assignment, was arrested by the NIS for leaking the identities of defectors to the North. Reports state that data on as many as 10,000 North Korean defectors might have been revealed.
Full story at the Chosun Ilbo.