I'm an athiest. Sam Harris is a pompous idiot. He does not represent all atheists, though I bet he wishes he did.

Sam Harris is at least smart enough to understand the importance of objectivity in moral theory, which is why he argues for an objective morality separate from religion (though he fails miserably at this).

Natural Law = Do not harm others

Unfortunately, it's not that simple. For one thing, there have been numerous men throughout history who don't give a damn about your moral formula, and I think you would be hard-pressed to explain to someone like Genghis Khan or Tamerlane why they should relinquish all of their power and privilege (which is based on domination over others) and live like an ordinary person. Second, it is not exactly straightforward what constitutes "harm" and what doesn't. For example, does usury count as "theft", and therefore as "harm"? What about adultery or fornication, even if entirely consensual? If a wife cheats on her husband or a husband cheats on his wife, is the other spouse being "harmed"? Are their children being "harmed" by their actions?

I would argue, based on religious laws which I hold to be reflective of objective moral truth, that usury and adultery are both harmful to society as a whole and are emphatically immoral, and that people who are guilty of usury and adultery should be punished severely. But most atheists don't seem to have much of a problem with these things, considering how rampant usury and adultery are in modern Western society.