I'm going to post this, even though I will no doubt face the ensuing wrath...
There is an awful lot of killing talk here.
I sympathise with anyone who has lost a pet to a predator, as I know I would be devastated if it happened to me. However, I consider it to be my responsibility to ensure the safety of my animals. If a fox or a hawk took one of my birds, I would only blame myself for not being careful enough. Indeed, I accept that I take some risks in free-ranging my birds as I consider that they have a better life this way, even though they are not 100% safe. If I kept them enclosed (and at far less risk of predation) they would not live the type of happy free life that I want for them. I have tall fences and have been lucky so far.
I can see no reason for blaming a wild animal for doing what a wild animal will do, that is search for food. As humans, building farms, towns and cities, we are invading the habitat of the weasels and bears, etc. (NOT the other way round) so we should not expect them to suddenly change their behaviour just because we don't want them to come near our homes or take our domestic animals.
I would no more blame a grasshopper for jumping than a fox for taking a chicken. The best we can do is to take care of our animals as best we can, which includes trying to make sure that predators cannot get them. We just cannot go randomly killing wildlife just because it is behaving like wildlife.
I realise this is a bit of a rant, but I felt I had to respond in the same manner. I wish no offence to the OP, but I think we have to accept that we live alongside the "varmints" in this world, that we cannot and should not blame them and harm them for behaving naturally, and that in planetary husbandry terms sometimes it is us humans who are the real "varmints"