It's tough to imagine that, in the modern era, any group of people could continue to exist in complete isolation from the rest of the world. Nonetheless, an indigenous tribe that has remained out of contact with, well, anyone but each other has been photographed from an aircraft flying over the Brazil-Peru border. (For a complete gallery of the pictures, go here.) The images show red-painted tribe members armed with bows and arrows, prepared to defend themselves should the mysterious flying object—anthropologists note that they wouldn't have any concept of airplanes—present a danger. The photos have already nabbed international attention, as well as shined a spotlight on the threats to these tribes should illegal logging and other deforestation practices continue unchecked. Tribal rights group Survival International estimates that there are still 100 "uncontacted" tribes on earth, half of them in Brazil or Peru, and all of them in danger of being "eliminated" by miners, loggers, and other opportunists with an eye on the tribes' land—not to mention viruses and other diseases from chicken pox to the common cold, to which none of the tribe members have ever been exposed. With offerings like that, can anyone really blame them for pointing weapons at us?