My friend was doing some emergency relief and similar work in South America for awhile years ago. They had a pilot that they frequently hired, so he got to know him pretty well.

One of the cartels kept trying to hire him (the pilot, not my friend) because of his experience flying in and out of rough and makeshift areas. He said the only reason he was able to turn them down and not get forced into it was that he had once flown the niece of a higher up member from a remote village to a city for emergency medical treatment. But he had known other pilots who were basically forced into it, with the whole offer of "silver or lead?" He himself didn't want to get involved simply because once you're in, you're basically always at their beck and call no matter what. He made enough as it was to live a modest but content and happy life, and what good is money if you get arrested and are behind bars, especially since cutting a deal isn't exactly an option.