So if I put on a nazi blog that said something akin to um I’m going to kill all of you… Given I don’t know who they are beside username and where they are at would I be arrested? How is that different from what the 20 year old did? He was just more specific as far as I can tell.
You live in a zero-tolerance world where that sort of scenario lead to the deaths of many people. It is a terroristic threat and people will take it seriously.