Stories about elephants that intelligently attack villages and essentially wage war are simultaneously creepy and not at all surprising. I remember first "getting" that animals exhibit this kind of "human" behaviors when watching chimpanzees doing organized hunting of monkees on a Trials of Life video in Mr. Bakke's biology class in high school. So, finding out that another species does it too doesn't surprise me.
That finding fits in nicely with the more widely reported story of elephants joining the small list of animals that recognize themselves in a mirror.
It seems like we've only just scratched the surface of really understanding the animal world and what goes on in non-human skulls.