Is unwanted touching ever legal? As a general matter, unwanted touching of one person by another is not lawful. But is there ever an exception? For example, when limited available space requires it. Like, for example: In a crowded elevator? In the bleachers at a crowded football game? On the sidelines of a crowded parade? Other crowded or enclosed spaces? To the letter-of-the-law, is that still illegal? Or is there an exception made in the law? For clarity, I am not referring to inappropriate touching. I'm just talking about the normal kind (brushing and bumping elbows, shoulders, hips, etc.).
To use Texas as an example: Sec. 22.01. ASSAULT. (a) A person commits an offense if the person: (1) intentionally, knowingly, or recklessly causes bodily injury to another, including the person's spouse; (2) intentionally or knowingly threatens another with imminent bodily injury, including the person's spouse; or (3) intentionally or knowingly causes physical contact with another when the person knows or should reasonably believe that the other will regard the contact as offensive or provocative. If no reasonable person would think the contact is offensive, and no injury is involved, no assault was committed. This is a fairly common definition of "assault."
Owing to the First Amendment, in the United States your recourse would be limited to civil action based on violations of terms of service (meaning that "the authorities" are not going to knock on their doors to tell them to behave). This is not "spam" (which could be regulated) as the term is generally understood. It is annoying, but probably does not constitute threatening or child porn. It might involve violation of an anti-impersonation law such as this one from Texas, if the offender uses the persona of a real person as opposed to a fictitious person). That law, moreover, does not criminalize simple annoying. Prosecution may be possible in the UK.
So for your first question, yelling "Stop Thief" loudly at the thief is perfectly legal (Like Yelling "Fire" in a crowded theater, it's legal if the theater is infact, on fire... the quote implied that it was a prankster who drew amusement from the reaction of the people who took him seriously). This may alert store employees, who have a specific kind of Citizens Arrest Power known as "Shopkeeper's Privilege" and is a reduced liability compared to Citizens Arrest. This is also pretty basic self defense agains people who are not engaged in any physical action against you but are starting to scare you. Suddenly shouting draws attention to you and discourages them from their behavior "I SAID DON'T TOUCH ME" being suddenly shouted in a Wal Mart is going to get notices from the immediate crowd drawn to you, and by poximate location, the person who is making you uneasy. For your second question, maybe, it depends... since the cop is clearly chasing the guy, you meet the qualification to use non-deadly force in stopping the criminal (i.e. you are witnessing a person committing a crime, in this case, resisting arrest or persuit) and it would certainly be reasonably non-deadly force if you were to trip, grab, or push the fleeing suspect. Citizens Arrest doesn't specify a minimum time to qualify, so if the officer is seconds behind, and you detain the criminal in this action until the gap is closed, it still counts.
Can a state declare: &quot;any violence against insert a group here shall not be prosecuted,&quot; which is pretty much what Nazis and Communists did, and then claim non-involvement in the violence that would ensue? This would be a violation of the Equal Protection Clause. https://www.justice.gov/crt/guidance-regarding-use-race-federal-law-enforcement-agencies goes into exhaustive detail on the topic of what may constitute an illegal abuse of selective enforcement. A key quote is highly relevant to your question: [T]he Constitution prohibits selective enforcement of the law based on considerations such as race. There is a lot of case law on this topic. This is frequently discussed in the context of race (especially profiling).
You don't have to interact with people if you don't want to If you don't want to talk or otherwise interact with somebody in a personal capacity, you don't have to. Your reasons for doing so are your reasons. Some of the congregation may have roles that require them to interact with Jane in what I will loosely call an &quot;official&quot; capacity. For example, if one of the congregants is a government employee and government business requires the interaction, they would have to do so. It gets a little tricky when there is not a clear legal duty to interact. For example, if a congregant is an employee of a company with which Jane has business and who would normally be the person to interact with Jane, they might reasonably claim that they have a religious belief that prevents them from doing so. Anti-discrimination law may require the employer to make reasonable accommodations for that belief, for example, by getting a different employee to interact with Jane.
You have misread the DMLP page. In Pennsylvania, it is illegal to record a conversation if you are a party and if the other party does not consent. The fact that federal law doesn't ban something doesn't mean that states can't ban it. There is generally a presumption that when both the feds and the states can legitimately regulate something, the feds weren't trying to preempt all state laws on the topic. While people often say "federal law takes precedence over state law," the normal rule is that both laws apply; the federal law only blocks the state law if the feds wanted to block said state laws. So far as I can tell, the federal law has never been held to preempt two-party consent laws; the point of the federal law was to restrict recording, not extend it. It's like how federal law doesn't prohibit taking hostages inside the US to coerce a private company into doing what you want (anti-terrorism laws might, I guess, but the federal hostage-taking law doesn't); while the federal law excludes most hostage-taking in the US, that doesn't mean that it's legal to take hostages. Congress sometimes wants to establish nationwide standards for something, but the presumption is that they didn't.
Anti-discrimination laws apply to certain protected classes only. Homelessness (real or assumed) is not one of them, so it is perfectly legal to bar such people from your premises. It is also perfectly legal to bar people with red hair (assuming this is not indirect discrimination against certain racial groups). Nobody is required to serve everybody who comes in; what you are not allowed to do is ban women, homosexuals or other groups set out in the applicable statutes.
This varies depending on the specific law of the state or locality involved. In New York, the word &quot;POSTED&quot;, along with the name and address of the owner is sufficient to notify people not to intrude, and anyone ignoring such a sign is technically trespassing (although, in practice, if such a person leaves the property when asked, did no damage, and appeared honestly ignorant, it is likely that no legal action would be taken). In California, as specified by penal code section 553 (quoted in the linked answer) a sign for this purpose must include: the words “trespassing-loitering forbidden by law,” or words describing the use of the property followed by the words “no trespassing.” in letters at least two inches tall, and follow other specifications in the law. The word &quot;Posted&quot; is neither required nor sufficient, although the law calls land with such signs &quot;posted property&quot;.