My worry - How much of this is kids talking stupid, and how much was a real threat?
Kids (adults, too) say a lot of things they will never do and would be unable to carry out, even if they wanted to do so.
It's true that kids will make threats but not intend to carry them out. That's probably why later other kids say, "He always said he would do it, but I thought he was just talking." What kid doesn't have revenge fantasies?
But, in the NJ case, the teens not only made the threat on the internet but also attempted to buy arms twice from underground dealers. In KS, the teens had the plans and the arms.
I wonder how much prison time they're looking at for planning but not carrying out yet? In our school district, students were arrested for making prank bomb calls and placing a fake bomb on the roof of the school, and at least one of them did two years in jail.