The need to continually update drug policy has made it a particularly volatile area of the criminal law. The purpose of drug-related crimes is to prevent drug abuse. Drugs are therefore categorised according to the degree of harm likely to be caused by their use, and the higher the category, the greater the penalty for the drug-related crime. Being found in possession of a controlled drug in any of these given categories can have significant consequences, and may involve either a period of imprisonment or a fine, or a combination of the two.