Has fracking caused tap water to become flammable?

Stories abound about fracking causing tap water to become flammable. Here's a video of one such case. I first remember these videos becoming prominent when the movie Gasland came out. Like that documentary, these videos seem to be put out mostly by organizations that have an agenda, so I'm skeptical.Have independent researchers ever confirmed fracking as the likely cause that someone has flammable tap water?The sort of evidence I'm looking for is ideally a peer reviewed paper in a major journal but if that doesn't exist then a statement from an...Read more