This is why libertarianism doesn't work. It just doesn't take into account how stupid people are.

Yes it is your property. No you cannot dig a 60 foot shaft in the suburbs. No, you can't do whatever you want on your own land, you will kill yourself or others.

Sheesh. And will anyone bother to tell him that metal detectors don't even detect things more than 1/2 a meter underground? Or that the more likely explanation is that his soil has a low level of conductive or magnetic material that is setting it off? After 60 feet this guy didn't check the owner's manual telling him that most objects detected will be less than 20cm underground? What a dumbass.