I might be wrong, but I'm sure I read a detailed discussion somewhere about how they analyzed burial pits and found large amounts of cuts as if the flesh had been flayed and so on. Apparently they did detailed DNA analysis and even found human bone fragments in waste pits.

I can't seem to find that discussion online right now. However I did find a rebuttal by Jared Diamond on the same site to this argument;

http://www.marklynas.org/2011/09/the-myths-of-easter-island-...

On a side note I think that it is uncomfortable for us to think about the demise of everything we cherish in this way, and that's why we tend to shy away from discussing this more openly and rigorously.

It's interesting to see how the blog post I cited ended with the same note;

>>>The islanders did inadvertently destroy the environmental underpinnings of their society. They did so, not because they were especially evil or deprived of foresight, but because they were ordinary people, living in a fragile environment, and subject to the usual human problems of clashes between group interests, clashes between individual and group interests, selfishness, and limited ability to predict the future. Does that remind you of any problems that we ourselves face today? That’s why we find Easter’s story so gripping, and why it may offer us lessons. You’ll find good coverage in Bahn’s and Flenley’s new book.<<<