A redated post.
An implication of utilitarianism that I have never heard discussed much is that pain turns out to be a fate worse than death, according to it. If the calculus attempts to determine what is right based on whether something produces the best balance of pleasure over pain, who is or is not dead seems not to count. Death is just a way of going to zero: no pain and no pleasure either. If you are a utilitarian and you know how to put people out of their misery painlessly, maybe a career as a serial killer is morally obligatory for you.