We have to get rid of that stupid statement, "taking the law into your own hands". Of course, you can't walk up and down main street, arresting people at gun point, willy-nilly. But you can't rely on the police to be everywhere at once, either.
When seconds count, the police can be there in minutes – and it doesn't matter if you live in the city or the country. There is no law between the time you call 911 and when help finally arrives. If you don’t take responsibility for yourself, you're going to have a chalk outline drawn around you, or your kid's dead body. Of course you have to take the law into your own hands. It's called, "responsibility".
I keep a loaded fire extinguisher under my kitchen sink, in case a fire starts in my home, because I know that it would be most likely out of control by the time the fire department arrives. I don't consider the use of a concealed fire extinguisher to be "taking fire prevention into my own hands". I consider it taking responsibility for my own family, our lives and our property.