The demand for Robusta coffee beans–the kind used to make instant coffees like Nestle’s Nescafe–is so robust that Indonesian coffee growers have taken to illegally clearing parts of the country’s national parks in order to grow more of this lucrative crop.

The illicit coffee growers are displacing the wild elephants who live in these parks, causing them to, well, run wild and trample the encroaching plantations. So the coffee growers have been killing the elephants, whose numbers are dwindling as their habitat shrinks.

And all this so westerners can have their instant coffee. Nestle buys a lot of coffee from this region, and 40 percent of it comes from local traders, but a Nestle spokesman told ABC News that Nestle doesn’t know where the beans actually come from:

“It might come — we have no way of knowing — from illegal sources. Law enforcement is not our task. We are working with local farmers to increase output from legal, existing plantations.”

The World Wildlife Fund has spent a year investigating Indonesia’s illegal coffee trade, trying to stop the slaughter of the elephants. Adam Tomasek, who works for the WWF, asked ABC News:

“How does a coffee producer in Europe or North America know that the coffee they’re buying hasn’t come from here? They don’t. And that’s actually the root of the problem–a consumer can have absolutely no confidence in what they are purchasing.”

Learn more about the WWF’s efforts on behalf of the elephants here.