I walked outside, still in my robe, and found my neighbors outside, also in their pajamas. Drivers had pulled over and stopped their cars. That event, and its aftermath, is a part of my life experience in a way it would not have been had I lived anywhere else. There are fewer identifiable groups now than there were several years ago, but research indicates that today's participants are often more hate-filled and prone to violence than participants of the past were. Any domestic group which desires or seeks the destruction or overthrow of the government, for any reason, may be considered a patriot group.
Militias are a specific type of patriot group.
They may stockpile weapons and explosives, practice military maneuvers, and plan warfare against the government and its citizens, much like any terrorist group. The members of these groups seem quite fervent, bordering on the fanatical. Our government, thankfully, tolerates a wide diversity of thought, criticism, and even hate, directed against it and its citizens. What is not protected, of course, is violence, or the planning of violence. That is a crime.