It absolutely is. I have two GSD's that are thankfully contained inside of Invisible Fence. They are EXTREMELY territorial with regard to other animals, and have made that clear to a few neighborhood dogs unwittingly coming on to the property. The other dogs are fine. Did I sympathize in a small way? Of course. If the shoe had been on the other foot, I would have completely understood a reprimand. The AR-15 was over the top though. Our fence came at a considerable expense, and every neighbor clearly realizes I respect the leash laws. Others don't, and that's very aggravating. It's one thing when a dog breaks free (and hopefully, the owner makes an effort to correct the containment issue); And it's another thing when an animal owner simply disregards the law and any respect for others who otherwise abide by it. But no matter how aggravated I've ever been, I've never yet given consideration to killing someone else's pet.