The criticism I level at Hitchens is that he wants the criminal law to enforce morality, whereas I assert that the criminal law should be tasked with no such responsibility, and that it should only be to uphold property rights.
I use the term property rights in the Lockean sense. Thus one's property encompasses not only inanimate objects in one's possession, but also, and most essentially, the physical body. Therefore all acts which I believe should be considered criminal acts involve a violation of property rights, whether it be of another's physical body or their rightfully-acquired possessions. Readers will do me a service if they can name anything which falls outside of this definition.
Morality is another matter entirely. For starters, morality is subjective. What is immoral for some is not so for others. This does not mean, of course, that there isn't broad agreement in society with regard to the categories of moral and immoral.
It is also the case that there is a significant overlap between criminal acts and immoral acts. But this should not obscure the fundamental difference between immorality and criminality. Moral law, if I am allowed such a term, is far more stringent than the criminal law should be. God's standards are over and above those of the criminal courts, and I doubt if many would wish to see people hauled into court for coveting their neighbour's wife or for sinful pride. Anchoring the criminal law to a defence of property rights has the benefit of making matters far simpler. It allows an objective set of rules to be applied.
With regard to Hitchens, the matter at hand was drug prohibition. He considers that taking drugs for self-stupefaction is immoral, and many would no doubt agree with him. However, what he has so far failed to do is establish how such immorality violates anybody else's property rights. Whatever harm comes to the drug-taker from his own action is wholly outside the limits of criminal law. If taking drugs leads the taker to rob or steal, then it is the subsequent acts which are criminal. It makes not a jot of difference whether the thief does this deed in order to buy drugs or to buy his child a birthday present. The crime is the same, and the victim deserves recompense.
I would also cite this distinction (and have done so) with regard to the death penalty. Whatever reasons against the death penalty, I would assert that, morally speaking, many murderers do indeed deserve to die for their crimes. This does not, however, mean that I think the criminal justice system should carry out upon them the punishment they deserve, even if it be arguably moral to do so.