I've heard of the Sentinalese! Is that the island where that missionary went a couple years back and got killed and the government was like 'sorry guys, we're not even going to get his body back, but we DID tell you not to go there'?
I guess in the case of the missionary he probably went because he thought God wanted him to but if God wanted that wouldn't he have made them less likely to spear people bringing Bibles? I'm not really very religious so the whole missionary thing just seems really pushy.