Fracking is a slang term for hydraulic fracturing, a procedure of creating fractures in rocks and rock formations by injecting fluid into cracks to force them further open. The larger fissures allow more oil and gas to flow out of the formation and into the wellbore, from where it can be extracted. Fracking has resulted in many oil and gas wells attaining a state of economic viability, due to the level of extraction that can be reached.
Fracking has been around since the end of World War II, but it was only in the last decade or so that the economic incentives helped to make it more common practice. The result has been an increase in oil production — and an increase in controversy.
Gasland, a 2010 documentary, and Promised Land, a 2012 feature film starring Matt Damon, helped to turn public opinion against the process. The information in those films has been effectively rebutted, but the damage has already been done. According to a 2013 University of Texas poll, 41 percent of Americans oppose fracking.