Mc Stain, as one of his last acts of treason, got legislation passed that Congress can use the military to protect themselves from the military. Posse Comitatus just keeps them from acting as military in uniform. We used to get hired as security to raise money for the booster club and we'd kick the shit out of drunk assholes, it sucked because we didn't have a choice because I was on active duty. There's always a work around.