I think you should report him to the authorities if he's participating in human trafficking. Don't bother with his friends or family. It's the authorities who need to know what he's doing. Do you have proof? If you have proof, you have to go to the police with that proof immediately. Not sure why you think it's your job to tell his friends and family that he's trafficking people? They'll find out from the media. If you do community outreach to make the community aware of the dangers of human trafficking, then your job is to report this man.