Comment by dissent
Some people broke the law, and the poster can be held accountable for successful incitement. It's not the post that broke the law per se.
You can yell fire in a crowded theatre. Just hope you don't cause a panic or you'll be in trouble.
Well, the test is if it's directed to and likely to cause a panic (in the US). So if you avoid causing a panic by sheer luck - like something counteracts your yelling and everybody settles down again, and that's the only reason nobody was crushed - you're still in trouble.
Though moral luck is certainly a thing in general, where negligence and risk-taking is not a crime until it goes wrong.