Yep, the militarization of police departments play into this thing too.
Here's something scary for you. I have a good friend who's currently a company-grade officer in the Army (who's leaving at the end of the year out of disgust after 10+ years of service and a tour in Iraq). He told me last week that he actually had to explain to another officer, a West Pointer (!), what Posse Comitatus was.
True.
1. Attending a military academy doesn't mean you are gifted with boundless knowledge and intellect or that you stayed awake in every class.
2. Unless a member of the military is participating in a mission that affects the civil population (civil unrest/ natural disaster/border defense, etc...) they don't get briefed on Posse Comitatus as a constraint to their mission.
It could be that the officer in question just never had those experiences and the first time he heard the term was from your friend.
Scary but what is scarier is that good people are being pressured out by the liberal-fascist atmosphere. I always thought that obola's sanction of gays was not about gay rights; rather it is an effort to infiltrate and subvert a conservative institution, i.e., the military.