What all these things demonstrate is that some people have no compassion, which I think is a very sad indictment for mankind. To kill is one thing, but to have not a jot of feeling for the one you kill (whether man or beast) is very, very sad.
Where I live we have seen children trample a fawn to death, a man decapitate a swan and I read somewhere of children who suffocated small kittens in a bag.
Why?