A burglar alarm. Think of it this way: you don’t want to have to shoot anyone with a shotgun. For one thing, it’s a messy business. Imagine blasting someone with a cannon at short range. Like that. For another, it’s traumatic. Some shotgun gurus say that a successful shooting will not leave you emotionally scarred; you’ll realize that you did the right thing to protect yourself and your family. You’ll feel the satisfaction of a triumphant warrior. Bullshit. The moments preceding, during and after the murderous mayhem may not haunt your dreams, but they probably will. Besides, it’s not all about you; do you really want your wife and/or children to see a human being blown to bits? And then there’s the fun of dealing with the police and the judicial system . . .