I can sort of agree with utilitarianism in principal, but in real cases, it is exceedingly hard or impossible to work out the total net result of any action. Someone might watch some totally contrived cases on "24" and then think "Make a note to Justice Department: Torture OK". You don't have the omniscience that the screenwriter passes to the viewers, and you can't count on secrecy (i.e. on not setting a precedent for the rest of the world). Lots of people are liable to imagine, in a crisis, that torturing this person will have an overall good effect, and I think they are at least 99% of the time wrong.

And yes, given the hundreds of millions of people involved, I wouldn't argue against the proposition that any tax will cause somebody's death. But that's trivial. Any change will likely cause somebody's death due to some butterfly effect or other, and NOT taxing is clearly no exception, since taxes pay for police, firemen, etc. I'm not making this argument for taxes; I'm just saying the argument is no good.

IMHO most non-religious ethical principles have something to recommend them, and should probably be invoked in the most extreme and obvious cases that don't involve serious harm to an innocent person. It's one-principle people who think they can do all the moral math that scare me.