There is a rancher/herder?? ( has over 6000 sheep) about 25 miles south. He has an alarm system installed on his tractors. Works like the alarms on cars. Its motion sensing.
You move his equipment without turning off the alarm and the devil himself will hear it. It has an amplified woop - woop siren and an old firehouse clang-clang bell mounted on the barn. He said it can be heard for five miles and from his demonstration - I believe it. At 250 feet - its so loud that it hurts your ears.
There is always somebody - somewhere on his property - that can respond to this system, if its set off. And all his help are always toting a rifle(coyote control).
I would guess at some point or other he has had trouble with thieves. I doubt, with this system, he worries about theft very often.