I have several customers who keep weekend/country retreats here, but live elsewhere. They are constantly battling theft and vandalism, many of them having suffered multiple intrusions. In my desk drawer out in the shop, I keep keys and garage door openers for probably a half dozen of these folks, and have for years. When their equipment needs attention, they call me and I go pick it up at my convenience....no need for them to come down and let me in that way.
last year I got a call from one of these customers at the end of the season, asking me to please pick up his tractor and service it for the winter. I've got keys to the gate, as well as the barn, so no problem. This fellow's property lies off of a well worn county road...you have to drive across a hayfield, then down a hill just to reach the gate...after which you travel another quarter mile or so to the house. Remote, is an understatement.
When I reached the gate, it was standing open. I drove on up to the house, where I found two pickups and four guys, none of which was familiar to me. The door to the barn where the tractor is kept was open, as was the front door on the house.
I wasn't sure what to do, so I jumped out with my clipboard, whistling, and a big grin on my face. I acted like I had never been there before, and had never met the owner. Told them I was there to pick up the mower. Since my truck has signage on the doors, they believed me, and I drove it out of the barn and on the trailer. Laughed and cut up the whole time, acted like I hadn't a care or concern in the world. I did however, get a look at both license plates.
As soon as I got out of sight I flew back to the shop and called the owner, a partner in a prominent law firm, and gave him the license numbers and a description of the vehicles. He had given no one permission to be there. It was looking dicey, and he called the police.
Long story short...his father, also a partner in the law firm, had allowed some of his friends to use the place as a hunting camp, and hadn't mentioned it to anyone... no harm, no foul. Other than my frayed nerves.
In my opinion, all the sophisticated electronics in the world won't do nearly as well, or be half the deterrent, of a good neighbor. Someone you can trust, and who lives close enough to keep an eye on things, and, lets it be known that he's keeping an eye on things.