Michigan had a desuetude incident a few years ago with “The Case of the Cussing Canoeist.” Apparently, a guy out in a canoe got mad and cursed a blue streak. He was then charged with violating an old law which makes it illegal to swear in the presence of of women or children. Eventually, he won in court. I wish I could have asked that prosecutor, "Dude, don’t you have anything better to do? :dubious: "
MALLUM IN SE Lat.: evil in itself. Evil as adjudged by a civilized community; refers to an act or case involving conduct punishable because of the nature of the conduct, not only because the law has declared it punishable.
MALUM PROHIBITUM Lat: wrong because it is prohibited. Made unlawful by statute for the public welfare, but not inherently evil and not involving moral turpitude.
I am going to advance a “fact” and then ask the Dopers-at-Law to clarify it. For U.S. citizens, in addition to desuetude, there is also the Fourteenth Amendment guarantee of equal protection. As I understand it, this is pretty limited but can be a valuable tool in defending yourself. If there is a clear-cut pattern of inequity of enforcement (e.g., all the cars stopped for speeding happened to be from out of state; of the 14 people at the party, eight were arrested, but the chief of police’s sons and the mayor’s son and daughters just happened not to be arrested) – then you may have a 14th Amendment defense.