[SteveZ]

The "shock collars" and invisible fence "minor irritant" collars always seemed to me like the precursor to tazing. I suppose as long as the FDA doesn't rule against their use on dogs, then small children left alone in a backyard will be next.....

The "invisible fence" seems to work with some of the breeds with little -to-no prey drive. One of the funniest things I ever saw was a neighbor's dog (Jack Russell Terrier) which used to go to the edge of the "buzz" range and stay there until the battery in the collar finally died - then the dog was off to the races!