"Extremist Activities" is pretty clearly defined in DOD policy, and included in that DODI as a reference. The DOD doesn't just decide groups are extremist willy nilly, nor does it use the SPLC list. Additionally, in my experience, soldiers that have run afoul of the policy by internet postings (as opposed to going to meetings or providing material support) are given a warning, and some more training on what is acceptable for a service member and what is not. JAG actually takes the 1A pretty seriously. It's much more common for a young O3 commander to be told "No, your soldiers
can do that" than soldiers to get hemmed up.
Again, I have seen nothing official from this change come down the Chain yet, so I suspect lawyers are *very* carefully going over the verbiage of the policy memo. We'll see.
For Reference:
(1) Extremist Activities. The term “extremist activities” means:
(a) Advocating or engaging in unlawful force, unlawful violence, or other illegal means to deprive individuals of their rights under the United States Constitution or the laws of the United States, including those of any State, Commonwealth, Territory, or the District of Columbia, or any political subdivision thereof.
(b) Advocating or engaging in unlawful force or violence to achieve goals that are political, religious, discriminatory, or ideological in nature.
(c) Advocating, engaging in, or supporting terrorism, within the United States or abroad.
(d) Advocating, engaging in, or supporting the overthrow of the government of the United States, or any political subdivision thereof, including that of any State, Commonwealth, Territory, or the District of Columbia, by force or violence; or seeking to alter the form of these governments by unconstitutional or other unlawful means (e.g., sedition).
(e) Advocating or encouraging military, civilian, or contractor personnel within the DoD or United States Coast Guard to violate the laws of the United States, or any political subdivision thereof, including that of any State, Commonwealth, Territory, or the District of Columbia, or to disobey lawful orders or regulations, for the purpose of disrupting military activities (e,g., subversion), or personally undertaking the same.
(f) Advocating widespread unlawful discrimination based on race, color, national origin, religion, sex (including pregnancy), gender identity, or sexual orientation.
Most recently "D" is what get's people hemmed up. One must be careful of what one says in public. FWIW, I haven't seen anyone get in real trouble that didn't explicitly call for violence to change something. I have seen a few folks get in trouble over it though.