It's funny because for me living rurally, it's kind of the opposite...I know EVERYONE who comes to the house and break ins are completely and utterly unheard of, so I am working to tone down Onyx's natural territorial aggression. I don't need a home security system, we don't even ever lock the doors.
I've actually been meaning to ask this question, I guess this is as good a place as any - to those of you with guardy dogs, what is your routine for introducing welcome guests to the house?
At the moment what is working for us is, I leash Onyx whenever anyone arrives and after an initial bark when they first come in the door, I generally distract her by asking her to do some stuff (basic obedience/tricks/whatever), and also reward for calm behavior (usually some look at that, too). Basically once I've distracted and given some treats, and a few moments have gone by, she doesn't even notice the new people so I can let her off and she'll generally just ignore them, maybe go greet them eventually. The one time I tried having someone else give her treats, she was super suspicious and didn't like it, so I won't do that again for a while. I should add, this is for people she doesn't know (or not very well), people she knows she will bark at but then greet happily once she realizes who it is.
I've never had an even remotely guardy dog before so it's all interesting and new. It's so interesting to see this behavior (just in the past while as she's getting older), she is totally social and happily greets strangers off the property, but she is definitely feeling the need to protect her territory as she matures.