Though we probably never think about it, there are many completely isolated and un-contacted tribes of humans living in South America. Living in isolation, these tribes have been relatively undisturbed by the modern world. In this video from the BBC, silent observer Jose Carlos Morales flies high above the tribes in Brazil in order to prove their existence to the Peruvian and Brazilian governments, who would much rather either ignore them or pretend they do not exist. Their land is in danger due to illegal logging, and the only way to protect them is to get the protection of the government. Any direct contact with outside humans from the modern world could prove dangerous, as they likely have no resistance to diseases we can easily fight, such as the common cold. Not to mention that loggers would likely just shoot them to clear them out of the land.