system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How are documentaries about drugs where they interview drug dealers who wear masks to hide their identity made? How The National Geo or Vice, for example, get in contact with those people and why they agree to get on the camera and risk getting caught?
gpt
They likely hired a "fixer."  The fixer is often a local journalist, maybe just someone that just knows a lot of people and has a lot of connections and can introduce the journalist to the people they want to interview and extend their own reputation to the journalist.  Fixers are crucial components of stories for foreign journalist.  They're often a mix between translator, facilitator, driver, bodyguard, etc.  Basically you'd have no chance at going and getting this story without first contacting a fixer who can make the right introductions for you and vouch for you.

In other words there's almost certainly a middle-man between the guys doing the interview, and the guys being interviewed.  They didn't just somehow cold-approach a big time drug dealer they had an introduction.

As to why they do it?  People love to tell their story to someone.  People like it when people are interested in them.