I can't recall a better illustration of this than this comment from the anonymous atheist commenter.
I had asked:
-This brings up a question, Anonymous, if you're still around - how do you know who deserves to live and who doesn't?
Simple. If you care about the person, the person deserves to live. Let those people who deserve to live, live. As for the rest of the people you do not care, they do not deserve to live. Let these people do whatever they want.