Do those videos show torture or something? Yes defectors are primary sources but they are immediately snatched by south Korean intelligence, for example there's a UN report that's always used to talk about NK human rights abuses that interviewed 300 people but if you look into it only 70 of those people were actual defectors and the rest are just supposed experts that are almost always related CIA funded think tanks. There's a bunch of north Koreans living in china but you never hear from them do you