Well, I just know what I read on like the Yahoo news site, I confess to not forging off with my packed high-protein lunch in search of any deeper truths 
I really don't see any just cause in feds arriving at a junior high school and hauling off a kid for a kiddy-post on their myspace page in a nation that prides itself on their freedom of speech. I can't recall the exact quote, but I recall it a was a real kid type post something along the lines of "well if the president wants everyone to go to war, he should have to go there too and maybe a bomb would hit him and he would die and he wouldnt like it so much". Something like that....
You better watch it now, this post could be interpreted as an indirect threat.

FWIW, I think the military intelligence needs to study the extremist groups, read their literature, and understand their whole socio-cultural background, their history, everything.
Instead of using their own parameters for interpreting what is a threat.
Get inside the head of the dangerous elements. Understand them. Then they can be stopped.