Why do you believe that a satanic force that tricks a person now has all the responsibility placed on it, and it alone? The person is responsible for listening to God and His wisdom and not being tricked. The devil is just doing his job. We open the door to him. And yes an african tribe that doesn't know or worship the one true God, will not be safe from such a thing. That is why it was so critical that the Good News spread as quickly as possible, so all would have a chance to know the truth and be saved.