Feeding feral cats can be a bit of a commitment. In some places, the cats can be trapped, spayed or neutered then returned to their environment. To me, this is the most humane solution. However, not all states or counties encourage this.
A cat does hunt. This, of course, is in its nature. But what happens when the native wildlife becomes endangered by too many wild kitties? Of course, this is a difficult problem. If only everyone would spay their cats, all could be solved. But I know this is a bit of a dream. There will always be irresponsible cat owners, who leave it up to the rest of us to take care of the animals they have dumped. In the meantime, I will continue to feed my feral cats, and hope that by doing so fewer wild birds will be caught.