Pet owners like those will just get another one when that one is gone... If it bothers you to see it kill birds and things, why not put food out for it yourself? That is what I would do and if all the neighbors fed it, it would be a fat happy cat. Cat food is not expensive and this poor baby could have a somewhat decent life. The shelter I helped out at would put all the ones brought in, in a trap to sleep.. Having helped at a kill shelter, I would NEVER do that to one of them and I advise anyone to do the same!