Criminal law is extending its boundaries to capture conduct that was previously described as civil or regulatory in nature. For example, in some jurisdictions public nuisance, trespass, throwing things at a sporting match, photographing people in private places without their consent and BASE jumping from a building, are criminalised. The unruly nature of criminal law is a serious problem for law makers who need to know what conduct should be criminalised and what conduct should not be criminalised to inform the scope of future criminal laws. It is also a serious problem for members of the community who need to know the minimum standards of behaviour. The unruly nature of criminal law has occurred because several principles underpin the deci...