The use of cannabis (also known as marijuana) for medical purposes is a notable 'medical necessity' case. Cannabis is a plant whose active ingredients are widely reported by sufferers to be effective in pain control for various conditions, usually neuropathic in nature, where common painkillers have not had great benefit; however as a Schedule I drug under the Controlled Substance Act, it is illegal and is targeted by government, police, and anti-drug campaigners: in some states, possession is decriminalized for even non-medical purposes, wherein other states possession is a felony offense. In this case the doctrine of medical necessity would be used by a patient who believed marijuana was beneficial to them if charged with use or growing/production of illegal controlled substance relating to marijuana.