Calm down! Do you really believe that every dog owner should be able to keep their dog in their yard at all times? Obviously they should try their hardest to do that, but if their dog does happen to go into someone else's yard, that doesn't mean they deserve to have their dog shot. Not everyone can afford a fence, and even when there is a fence, dogs sometimes manage to get out. If a strange dog is in your yard and it really is a threat, your best response is to go inside your house, call your neighbors to come get it, or the police, or just wait until it leaves. I have known several people who have had their dogs shot by neighbors, and I believe that in most cases the neighbors are just doing it to get back at the dog's owner, and to show how "tough" they are and because they know they can get away with it.