Fracking—using water and chemicals to literally force oil out of shale deep below the earth’s surface—has been around a long time. But, with the price of oil skyrocketing (and the cheapness of extracts from shale), it’s getting more attention—a lot more. While oil companies are using it more, the practice is under attack in the US and in Europe for risking pollution, and possibly even causing earthquakes. But wait; what is it and how does it work? Find out in two minutes.