I also have been here three years and don't think it's any better or worse now than when we arrived. Just a little more light is being shown into the darker crevices, is all.
As always, common sense applies. Don't carry large bills, expensive jewelry, etc. Don't sit out on your terrace with your laptop at 2 in the morning. Try to stay to well-lit paths (not always possible).
I wouldn't go so far as to say "Don't go out at night." But I WOULD say don't stay out til 4 in the morning and be obviously intoxicated. Don't be out late alone . . . etc.
And I would agree that living in a remote area requires some extra barbed wire and maybe cactus, and even then, if someone "hears" you've got money, it can make you a target. But in general, the thieves will choose the path of least resistance.
I worry about this "taking matters into our own hands" stuff. Unless VERY well trained and willing to do what is necessary, more armed guards will do little but to bring more arms.