That's some twisted thinking.
I don't think it's twisted. The feral cats are non-native and introduced by humans (and in some cases propagated by humans). If humans act to un-do their previous acts, the results of which they find to be deleterious, aren't they just recognizing and rectifying previous mistakes?
House cats are not native to the Americas, so killing them is restoring nature’s balance. I think it’s your thinking that’s a little fuzzy.
I love cats but feral house cats are not pets and generally want nothing to do with people. They spread disease, make a racket (and a stench if they take up living under your porch or someplace like that) and kill wild birds. Although, I’ve read that it’s actually well-fed pet cats that are the most dangerous to wild birds, while feral cats tend to concentrate more on easier to catch rodents.
It's twisted, all right. This guy seems to think that feral cats are obligated to follow the Endangered Species Act, and he's appointed himself the enforcer.
Feral cats aren't indigenous to North America. They're a threat to birds, and they crowd out foxes and owls and other indigenous predators.
Animal welfare groups are split on what to do about feral cats -- some of these colonies are several generations old, long removed from contact with humans, so the cats aren't candidates for adoption. If they go to a shelter, they'll be killed.
Some groups are practicing TNR -- trap, neuter, return -- in the hopes that the colonies will gradually die off from attrition. The Humane Society doesn't have a national position, but a lot of its chapters support TNR, and they've recruited volunteer vets to do the procedure for free. The plan is that they don't need to kill the cats, but the colonies will fade out by attrition when they stop having new kittens.
The Audabon Society, on the other hand, wants the cats caught and euthanized, because they're more concerned about the birds.
That doesn't justify plinking at cats with a .22. Note that the charge is cruelty, not killing. Trapping and gassing stray cats is legal; winging one and leading it to die slowly, not so much.
IMO, this guy was doing the "right" thing.
We are all part of nature, aren’t we?