Assuming we agree that the actual harm is not the pornography itself but rather the actions viewing it might elicit, I think supporting a law like the Criminal Justice and Immigration Act on utilitarian grounds is an uphill battle. If these laws reduce the availability of violent pornography, then, those who use the pornography as a substitute for engaging in the abusive behavior might well be driven to acts of violence or child molestation.

Unlike blanket prosecutions for possessing child pornography, a prosecution for attempted acts of molestation based on possessing child porn rightly focuses attention on the accused as an individual rather than people who possess child pornography as a group. Child pornography and violent pornography likely has different effects on different people. Someone accused of attempted molestation can pursue a defense that the pornography was used for cathartic purposes. Making possession itself a crime eliminates this defense, consequently reducing the accuracy of the prediction about that individual's likelihood to molest in the future.

As for the privacy argument you bring up, Josh, I would constrain it in two ways: First, someone's sovereignty over his home clearly can't be absolute. Fiefdom or not, I believe we can all agree that people should be prosecuted for some crimes--murder and fraud are easy examples--even if they are largely carried out behind closed doors. Secondly, and related to the first point, many actions performed within one's home have direct effects outside that physical space. Physical barriers like the walls of your home or even your own computer have little value when dealing with online activities. The government is forced to pay more attention to what you do in places that used to be considered private. At the same time, the surveillance is, at least in some sense, less intrusive in nature; physical searches are replaced by electronic monitoring. One can be both more closely watched than before and yet less inconvenienced by it--depending on how the information that is gathered is used.

-- AndreiVoinigescu - 07 Sep 2008