The First Amendment disallows the government from impeding free speech. How does that interact with what appears to be civil matters presented here?

@GregoryCurrie It means that the government can't force you to speak or not to speak. So you are free to sign NDA and not speak up and government can't punish you for that.

Correct. The courts are as much a part of government as Congress or the police, so when someone hauls you in front of a judge on a defamation or negligence claim, the court usually can't take any action based on your decision to speak or not speak. The fact that you're in court on a civil vs. criminal matter is largely immaterial.

@bdb484 The first amendment specifically deals with congress, not the executive branch, nor judicial. You can absolutely be found liable in a civil case, if you had a contractural obligation to speak about something and did not, for example.

@Mołot The court can actually "punish" you if it found you had some sort of obligation to speak out. You can look up the "duty to warn" concept for examples.

@GregoryCurrie That's a cute literal interpretation of the First Amendment, but that's not how it actually works. I'm already familiar with the "duty to warn" concept, which is why I addressed the duty issue in my answer.

@GregoryCurrie: If failure to warn gives rise to any claim at all, it would be some kind of tort. Libel is a tort, and the First Amendment obviously applies to libel, so the claim that torts are somehow outside of the ambit of the First Amendment must fail.

@bdb484 Sadly, you don't appear to be familiar enough.

@Kevin Affirming the consequent. I'm saying in specific circumstances, you have a duty to warn. The answerer here says that duty to warn cannot possibly exist because of the first amendment. Which is incorrect.

@GregoryCurrie: The answer does not say "cannot possibly exist" or words to that effect. It is well understood in American constitutional law that the protections of the First Amendment are not absolute. Just because speech is "protected," it does not follow that no regulation may ever attach to that speech. This is why the actual malice standard exists, rather than simply having a blanket "no such thing as defamation" ruling.

@Kevin "In the United States, that lack of duty is even more clear, because the First Amendment would protect your right to disclose or not disclose what had happened."

@GregoryCurrie: "Even more clear" simply does not have the absolute, categorical meaning that you want it to have.

en.wikipedia.org/wiki/Duty_(criminal_law) - Free speech has nothing to do with it. You either have a duty to act, or you don't. "When a person puts another in a position of danger, he creates for himself a duty to safeguard or rescue the person from that danger." - Only question is if the plaintiff put other people in danger, or is the company to blame from start to finish. If the company isn't, then they're under a court order to (personally) endanger other people (judge is also culpable).... Which is unlikely. - The "later victims" will win their class action suit.

@GregoryCurrie It's true that a person could assume a duty to warn -- perhaps by contract, perhaps as a fiduciary. But absent such special circumstances, the First Amendment does not allow courts to enforce a general duty to warn the universe about fraud, which is what OP is asking about. Because those special cases are so rare and not relevant to OP's question, they were ignored and lumped under the hedging language used throughout my answer ("most cases," "essentially," "likely"). I'm sorry this wasn't clear enough for you, but in fairness, you do seem to be the only one misreading it.

"the First Amendment would protect your right to disclose or not disclose what had happened. It does not allow courts to enforce a general duty to warn the universe about fraud."

This answer cites nothing and predictably gives wrong answers. @Mazura