Have you talked to this kid's parents at all? I know they're probably the ones who put them there. And so they're probably some of those TOUGHLOVE idiots who don't want to listen to anything. But it might be worth a shot to just give them what you know so far about the people they've turned their son over to.
Another strategy, when someone joins a cult like this, their neighbors and co-workers notice and gossip. You might try and connect with some adults who would be sincerely interested in their friends' wellbeing. `Course, things might be different in this case because, as I understand it, the parents don't get all that involved. They've just 'sent a kid off to private school'.
Are you still on for that protest? Taking a bull horn to the scene is probably the best way to send a message. Before you draw attention to yourself, though, you might want to try and find allies in town, or feel things out a little. See what the local sheriff thinks about all of this. Generally, Mountaineers hold personal privacy as a high tenet of the local culture. They won't give a crap what's going on on someone else's private property. But something like this is bound to bring trouble to the area, and they hate that more than anything, especially with WV trying to get in on the tourist industry.
Bottom line, a LOT of these kids have had good friends on the outside trying to get them out over the past 30 years. They're pretty good at preventing that from happening. Your friend is probably being told that no one outside the camp cares for him, including his parents. And after awhile, he might start to believe that. If he's not trying to break out or to contact you, that's the reason. But keep trying. Post missing posters with his picture around town if you're up for a confrontation. That might get some people talking. Might also get you a free stay in the local jail if law enforcement is on cozy terms with the school.
-If there's a worse idea going than locking kids up for victimless crimes, it's probably locking them in close proximity to some tyrannical altruist bent on helping them even if it kills them.
Saving our Children from Drug Treatment Abuse