Though it was not a good or ideal situation, the Amazonian tribe that took hostages to demand central aid from the government was justified in doing so. These tribes, like most native people in the world, live off of the land, and receive little to no help from the government. In addition, every year they lose more and more available land to development and progress, making it harder and harder for them to survive.
Although it was a very extreme course of action and of course terrifying to those taken hostage the people of the Amazon feel, quite rightly, that they are sometimes an ignored people. It is difficult for them to capture the attention and respect of decision makers across the world in any other way.
Putting humans in captivity is a grave offence against their freedom and is a somewhat aggressive mean of drawing attention. In fact, I would go almost as far as saying that this is no different than any criminal hostage activity, with only the "ransom" being labelled as "governmental aid" instead. If it were to be successful it would create a very bad precedence that others may feel enticed to follow, affecting the peace of the nation. Furthermore if Amazonian tribes are to lobby against any further environmental degradation of the Amazon, they would be severely discredited if they were to indirectly profit from it (in ways of governmental aid).
An Amazonian tribe was wrong to take hostages in its efforts to obtain aid from the central government. Although likely an act of desperation, violence and hostage taking is not the solution. There has to be other ways to get the government to act. This includes contacting the international press and organizations.
A lot of people belief that the end justifies the means. However, when it comes to putting innocent lives in danger, I have to say that it would not. While the tribe really needed aid from the central government, involving people who had nothing to do with the situation is not the way to do it. When demanding something, only involve those who are directly involved in the situation.