Fracking (hydraulic fracturing) involves injecting a mixture of water, sand and chemicals at high pressure underground to fracture rock formations and release coal seam gas. There is evidence it threatens our environment, with a particular threat of contaminating our water supply. The process has been banned in France, is subject to a moratorium in South Africa and is the subject of much contention in the United States, where "Gasland" was filmed. See www.gasland.com.au  For more information see http://lockthegate.org.au/