I stated this in another thread: They've attacked a federal installation and federal agents. While they have not used traditional weapons, nonetheless they have used items as weapons that can maim or even kill. They have stated their intention is to bring violence to the streets of the country, and possibly to overthrow the government. They have threatened average citizens' lives.

This is on the line of sedition (I'd say it meets the criteria if you really wanted it to, but it is at least civil insurrection with heavy seditious undertones). They should possibly be treated (depending on your patience for such things) as enemy irregular combatants and terrorists. That's a far stiffer penalty that one year in jail of pay out some money.