What's a militia?

I mean, if you get together and call yourselves say, a airsoft club or some kind of action shooting club or a hiking club or whatever involves shooting and skulking about in the woods-who's to say you meet their legal definition of 'militia'.

Doesn't mean you don't fulfill the role of militia with your activities you're just throwing up a legal speed bump. Just presenting an option unless you desire a confrontation. Given the current campaign against gun owning patriotic Americans... well things could turn hot real quick.