Wallabies, look here....

[5.56X45mm]

If you want to understand why we have arms and how they play in defense. Look at this topic here. Look at the series of photos so you can see how we the people use firearm to defend ourselves.

http://www.military-quotes.com/forum/american-militia-t23230.html

Those are all civilians. Not military, not police, not part of any government agency. They are all civilian militia.