Mala prohibita (the singluar is malum prohibitum) is a term applied to any action is criminalized strictly by statute and statutory law. The phrase is Latin, and translates as wrong because it is prohibited. This class of crime is contrasted with crimes mala in se, the Latin term for "wrong in itself," and both are taken directly from the old common law system. Consequently, not much weight is placed on them in modern courts, though the distinction remains an interesting one.
Crimes mala prohibita are usually those which incur no serious punishment, such as minor infractions and misdemeanors. However, the primary feature of crimes mala prohibita is not their lack of severity, but that they are acts criminalized by statute in an effort to regulate the general behaviors of society. As a general rule these do not include crimes that directly harm the person and property of others. Consequently, crimes mala prohibita do not usually carry powerful moral stigmas along with them. There is nothing wrong in itself with a Briton driving on the right side of the road, but it is still a crime malum prohibitum in the United States. Some familiar crimes mala prohibita are drug abuse, drunk driving, gambling, public intoxication, carrying a concealed weapon, and parking in a handicapped zone.
Crimes mala prohibita are sometimes powerfully established in the traditions of the United States, and sometimes so short-lived that they can even be called experimental. U.S. legislation is ceaselessly criminalizing and decriminalizing. In an attempt to optmize society's performance and prosperity, the criminal law is continually undergoing changes on legislative and judiciary levels and, because they exist more firmly in the letter of the law than in the hearts of mankind, crimes mala prohibita are the ones most often transformed.