An important case gets underway tomorrow in Boston: the civilian criminal prosecution of Tarek Mehanna, charged with an array of offenses stemming from allegations that he traveled to Yemen in 2004 in an effort to get training so he could go on to fight against U.S. forces in Iraq, and that he subsequently became involved in the online promotion of violent extremism. He has been charged with a variety of conspiracy and material support counts, as well as making false statements to investigators. Margot Williams has a nice preview on NPR's Two-Way here, and if you want to dig really deep into the prosecutions case, you might want to look at this 75-page detention memorandum from the time of his arrest (though of course you must bear in mind that this was no more than a proffer).
What makes the case particularly interesting, in my view, is the First Amendment angle in relation to the counts premised on his online activities. Mehanna apparently has requested a jury instruction on this issue, possible relating to the Brandenburg standard (i.e., that the First Amendment protects even loathsome speech unless it is likely to produce imminent illegal action). Many have wondered over the past decade whether and how judges would apply that standard in a post-9/11 terrorism-related case. Perhaps we will find out. It may also be that his request instead focuses on HLP v. Holder's application to this case. If and when I learn more, I'll post an update.