christopher ahn is an endangered man. >> this whole place is called -- >> we met christopher ahn is southernsed. ahn joined the marines and served in fallujah. when he returned from iraq, he got his mba and cofounded a consulting business. but seven years ago, the self-described do gooder picked up an unusual hobby, helping north korean diplomats defect. >> i don't think that i could morally look at myself in the mirror if i turned away from someone who was desperately asking for help. >> how many north koreans did you help defect? >> i always try to lean on caution and not really talk about -- >> but is it a handful, dozens? give us a sense of what we're talking about. or was this, you know, one or two and i'm out? >> it's more than one or two, and it's less than dozens. >> ahn says he did it with a secretive, makeshift group of activists who call themselves cheollima civil defense. they claim to have helped high profile north koreans defect. >> there were whispers within the north korean diplomatic community about this strange organization that was out there doing this. >> was it a loosely