> In the US, I believe threats of violence or harm are covered by the First Amendment
That's not true. That's way too vague and broad of a claim. In general, specific threats of violence and harm are explicitly not free speech and not protected. And if they're not specific, they're not really "threats". Incitement, fighting words, and other speech often involved in fights where violent threats are made (such as slander and perjury) are all US exceptions to free speech that extend past the imminent lawless action clause.
That's not true. That's way too vague and broad of a claim. In general, specific threats of violence and harm are explicitly not free speech and not protected. And if they're not specific, they're not really "threats". Incitement, fighting words, and other speech often involved in fights where violent threats are made (such as slander and perjury) are all US exceptions to free speech that extend past the imminent lawless action clause.
https://en.wikipedia.org/wiki/Freedom_of_speech#Limitations