I have cats. I've had dogs but I'm apparently not responsible enough for them. Having property for them to roam on I could never see chaining them to a tree or keeping them in a pen. They stayed in the garage and when they needed to go out they were free until they wanted back in. My eight year old Saint Bernard decided to tackle a semi late one night after years of avoiding the road. A year later my lab did the same. That was enough for me.
I can tell you firsthand that cats, whether domestic or feral, will hunt as a pack at times. My cats get fed very well and I've watched them corner and attack, or at least attempt to attack, possum, rabbits, squirrels, partridge, pheasant, and who knows what else. I had one cat disappear for an entire year. When he came back he was 4 times the size he was when he left. He was no small cat when he disappeared.
Now and then I'll hear a shot from down the road and realize a day later that my cat has gone missing. I don't doubt that the neighbor shot it and I don't fret about it. Not that I don't give a shit but what are the options other than walking over to someone elses home and asking if he just capped your pet. My cat may not have been feral but good luck determining that before you pull the trigger.
I would venture to guess that more cats have fallen prey to bobcats, coyotes, wolves, and raccoons, since their habits of hunting put them in proximity and direct conflict with one another.
What you do in the dark will someday come to light.