Finally put a name to it.

The current series I've been writing more or less revolves around a group of family and friends coming together to protect their communities and reshape the world. I've been trying to put a name to what their group would be labelled as. They're not exactly vigilantes because they don't go looking for trouble. They simply respond when it finds them. I was reminded today that civil defense is a thing in the military, but my characters are civilians with no official credentials. The best label I can think to put to that is an independent civil defense force since they're completely separate from the government, but they are well-trained and organized. A militia sounds too extreme to me because there are other implications that go along with that, but I don't know. You guys tell me what you think.