Maybe the Key word here is "threathening". Threats should be always looked as something to be careful about.

I have no Idea who are these people on the articule posted nor the context, but i think there is always a thin line between freedom of speach and respect of someone elses rights.

As an example, would you defend the freedom of speech of someone that openly do racists speeches, and start inciting people to punch kill a Black skinned person (or jew, or asian, or gay, or woman, etc) every?

Like i Said, i dont know the context, but we must have in mind that you must have freedom of speech, but also suffer the consequences of your words.