Despite the publishing of a Model Penal Code in 1962 by the American Law Institute, the criminal provisions of various states within the USA often conflict. The typical American can't hope to get acquainted with even a negligible fraction of his country's fiendishly complex and hopelessly brobdignagian criminal code. Such inevitable ignorance breeds criminal behaviour - sometimes inadvertently - and transforms many upright citizens into delinquents. In the land of the free - the USA - close to 2 million adults are behind bars and another 4.5 million are on probation, most of them on drug charges. The costs of criminalization - both financial and social - are mind boggling. According to "The Economist", America's prison system cost it $54 billion a year - disregarding the price tag of law enforcement, the judiciary, lost product, and rehabilitation. What constitutes a crime? A clear and consistent definition has yet to transpire. There are five types of criminal behaviour: crimes against oneself, or "victimless crimes" (such as suicide, abortion, and the consumption of drugs), crimes against others (such as murder or mugging), crimes among consenting adults (such as incest, and in certain countries, homosexuality and euthanasia), crimes against collectives (such as treason, genocide, or ethnic cleansing), and crimes against the international community and world order (such as executing prisoners of war). The last two categories often overlap. The Encyclopaedia Britannica provides this definition of a crime: "The intentional commission of an act usually deemed socially harmful or dangerous and specifically defined, prohibited, and punishable under the criminal law." But who decides what is socially harmful? What about acts committed unintentionally (known as "strict liability offences" in the parlance)? How can we establish intention - "mens rea", or the "guilty mind" - beyond a reasonable doubt? A much tighter definition would be: "The commission of an act punishable under the criminal law." A crime is what the law - state law, kinship law, religious law, or any other widely accepted law - says is a crime. Legal systems and texts often conflict. Murderous blood feuds are legitimate according to the 15th century "Qanoon", still applicable in large parts of Albania. Killing one's infant daughters and old relatives is socially condoned - though illegal - in India, China, Alaska, and parts of Africa. Genocide may have been legally sanctioned in Germany and Rwanda - but is strictly forbidden under international law. Laws being the outcomes of compromises and power plays, there is only a tenuous connection between justice and morality. Some "crimes" are categorical imperatives. Helping the Jews in Nazi Germany was a criminal act - yet a highly moral one.