In North Korea, it is a great privilege to take part in reunions with family members in South Korea, and families are carefully vetted for ideological soundness before they can be considered.
One defector who worked for the North Korean intelligence apparatus said the family reunions are overseen by the Unification Bureau of the Workers' Party, which receives applications from families seeking to participate. The State Security Department and Ministry of Public Security then conduct background searches of individual members.
North Koreans who are successful or have no record of mistreatment by the regime are considered for their propaganda potential, as they are more likely to praise the leadership when they meet their family from the South. Once selected, North Koreans then go through between one and three months of ideological education at the Unification Bureau.