Discoveries of indigenous tribes in Latin America seem to go hand in hand with their extinction, whether by disease or by design.

As developers and loggers go ever deeper into the rain forest there is usually a small window of time to protect discovered tribes from the near inevitable massacres and ethnic cleansing by land hungry peasants, loggers and resource hungry mining companies. Often latin american governments work hand in hand with the developers whilst simultaneously declaring out loud to NGO's and the UN about the efforts they are making to defend indigenous peoples' rights.

The schemes put in place to protect them usually involve removing the tribes or too enclose them in ever decreasing reservations that lead inevitably over the long term to the disappearence of their cultural identity and community cohesion even when they are not actually wiped out physically. Even the most hard nosed regimes in latin america try nowadays to avoid outright extinction of tribes but whilst ensuring their eventual destruction prefer to use tried and tested methods of misleading propaganda, obfuscation, intimidation and murder of tribal human rights defenders to make the world think that something is actually being done to help the threatened tribes.
ctd at:
 http://witnesshr.blogspot.com/2011/08/indigenous-amazon-tribe-in-brazil.html