When is ignorance a legal defense? In the United States, under what circumstances is ignorance of a law or legal principle a defense against legal action?
In general, ignorance of a law is an excuse only when the law specifically says it is. There are extreme cases where a law has been found invalid because it did not give people enough notice. Actually, only one case I know of -- Lambert v. California, 355 U.S. 225 (1957). The city of Los Angeles passed a law making it illegal for anyone who had ever been convicted of a felony to remain in the city for five days without registering as a felon. Lambert was arrested on suspicion of doing something else, but convicted for being an unregistered felon. The Supreme Court held that it was a violation of Lambert's due process rights to convict her of a crime she had no way of knowing about, or even suspecting. This is a very rare, extreme case, and does not apply to things where people might be expected to suspect that there might be a law. Otherwise, notice of a law is only required if the statute says so; for example, if a speed limit law requires the posting of signs, but the signs aren't posted, the law may not be in effect. However, ignorance still isn't an excuse--if the sign is posted, but you just didn't notice it, you're still on the hook.
The wording is a little confusing, but I interpret it as saying the following: Normally, discovery in a court case allows either party to demand documents from the other, to be used as evidence. However, our courts have exceptions; certain documents might be 'privileged against discovery', meaning they couldn't be demanded in that way. If one of those exceptions would apply to a document under court rules, then you can't request it under Freedom of Access either. To know what those privileges are, and how broadly they apply, you'll have to consult the rules of court procedure for your state.
1. Are this and similar ordinances constitutionally valid? Yes. Some future court might decide the law is invalid at some future time. But that possibility is hypothetical and speculative. Therefore, as of now, the law is valid unless and until it is challenged and overturned. 2. What defenses could a government make if challenged? It depends on what grounds the law is challenged. Your question about possible defenses is highly dependent on the nature of any challenge — which you have not specified in your question. The U.S. Constitution, for example, prohibits laws respecting a number of things such as freedom of the press, speech, religion, peaceful assembly, bearing arms, etc. to list just a few of the most notable ones. But your question does not assert the law in question violates any specific or particular prohibition against it. Although the question mentions "restricting free movement as well as targeting only a specific demographic," it does not specify any part of any constitution that prohibits these things. Therefore, your question is unclear as to what might present a constitutional problem for the law. It is also unclear which constitution you think might contain prohibitive language. Is it a federal constitutional issue that concerns you? Or is it a state constitutional matter? In either case, which issue specifically concerns you? Your question needs to address these specifics in order to analyze it and respond in a meaningful way. Look at it like this... just as it is impossible to prove a negative, so is it impossible for anyone to conclude with absolute certainty that any law is not unconstitutional because no one can predict with certainty every possible future challenge a law might face. There are just too many possibilities to (pre-emptively) exhaust them all with certainty. Also, no one can predict with certainty how any future court might rule on the future challenges (which themselves are unpredictable as previously argued). Therefore, one can only say I think the law is unconstitutional and here are my reasons. Then others can analyze the law and the reasons; then offer an opinion. Further, based on precedent, would they likely be successful? See above answer to question numbered 2. Laws aren't required to be "justified" by the constitution. Constitutional justification for a law is a meaningless phrase. There is no requirement for a law to be "justified" by any constitution other than that the legislature is empowered by the constitution to make laws. That's all the justification any law needs. Beyond that, however, no law can violate the constitution as determined by a Supreme Court (or the last court to rule) if challenged.
There is a legal concept of de minimis: the idea that some offenses, civil or criminal, are too small to be worth prosecuting. For example, a photograph of a city scene that incidentally captured part of a copyrighted billboard in one corner of the image infringes the copyright on that billboard. But if the copyright holder were to sue, it's virtually certain the suit would be thrown out due to the minimal nature of the infringement. Technically speaking, yes, what you describe is a crime. But any prosecutor who tried to bring charges to that effect is likely to be chewed out by the judge for wasting everyone's time. (Incidentally, assuming the reporter and property owner are US citizens, the crime is failure to cross at a designated crossing point (19 USC 1459, a customs offense) rather than improper entry (8 USC 1325, an immigration offense).)
See http://uscode.house.gov/download/download.shtml to start. But what exactly do you mean by a "law"? Lots falls under that term: do you include case law? SCOTUS decisions? Administrative policies? Read earlier Law SE question Naive approach to aggregating all US Federal Laws?
Contempt of court is when you refuse to do what the court (judge) orders you to do. Actually, you have been instructed by the judge to answer questions truthfully, so if asked, you are supposed to state your beliefs. Volunteering an unwillingness to apply the law as instructed is always an option, and will get you excused from that jury for cause.
In law, there is a distinction between mistake of fact and mistake of law. If the law prohibits X, and you think you're doing Y, that's a mistake of fact. If the law prohibits X, and you know you're doing X, but you think the law prohibits Y, that's a mistake of law. Mistake of fact is generally a defense (although that principle is being eroded), but mistake of law is not. In your hypothetical, you clearly had the intent to sell coffee, so you had mens rea. Mens rea refers to the intent to perform the act that is illegal, not the intent to break the law. If you intend to follow the law, but intentionally perform an act that is against the law, it is the latter that forms mens rea; mens rea refers to your intent regarding the act you are performing, not your intent regarding the law.
In your example, there is nothing that indicates to me that there is a "particularized and objective basis for suspecting the particular person stopped of . . . criminal activity". If you have described the totalilty of the circumstances, the officer does not have the right to arrest or detain the individual. To your broader question about how specific descriptions must be in order to provide a basis for a stop, the assessment is based on the "totality of the circumstances". For example, an anonymous tip that "a woman would drive from a particular apartment building to a particular motel in a brown Plymouth station wagon with a broken right tail light [carrying cocaine]" was enough to warrant a stop. Alabama v. White, 496 U.S. 325 (1990)1 In contrast, the court "determined that no reasonable suspicion arose from a bare-bones tip that a young black male in a plaid shirt standing at a bus stop was carrying a gun." Florida v. J. L., 529 U. S. 266 (2000) The “reasonable suspicion” necessary to justify such a stop “is dependent upon both the content of information possessed by police and its degree of reliability.” Navarette v. California 572 U.S. ___ (2014) In any case, a crime must be part of the particularized suspicion. 1. This case focused on the indicia of reliability necessary for an anonymous tip to support a reasonable suspicion, but it is also an example of a degree of non-specificity in identification of a suspect.