From the New York Times:
Experts have often wondered what proportion of men who download explicit sexual images of children also molest them. A new government study of convicted Internet offenders suggests that the number may be startlingly high: 85 percent of the offenders said they had committed acts of sexual abuse against minors, from inappropriate touching to rape.
Apparently, though, the Federal Bureau of Prisons does not want the data about on-line porn and child sex abuse to be made available. According to the Times article (full text here), “[T]he prison bureau in April ordered the paper withdrawn from a peer-reviewed academic journal where it had been accepted for publication, apparently concerned that the results might be misinterpreted.”
On the relationship between the consumption of pornography, Catharine MacKinnon said in her Francis Biddle Memorial Lecture at Harvard Law School in 1984 (reprinted in Feminism Unmodified):
In pornography, there it is, in one place, all of the absues that women had to struggle so long even to begin to articulate, all of the unspeakable abuse: the rape, the battery, the sexual harassment, the prostitution, and the sexual abuse of children. Only in pornography is it called something else: sex, sex, sex, sex, and sex, respectively. Pornography sexualizes rape, battery, sexual harrassment, prostitution and child sexual abuse; it thereby celebrates, promotes, authorizes, and legitimates them. More generally, it eroticizes the dominance and submission that is the dynamic common to them all.
Some second-wave feminists (e.g., the Feminist Anti-Censorship Task Force) reject MacKinnon’s harms-based analysis and caution against censorship. Post-modern (dare I say third-wave?) feminists suggest that pornography is “a way of seeing, a gaze” and claim “a more sophisticated approach to sexist imagery” that posits “the viewer’s activity in the production of meaning in pornography.” Kegan Doyle & Dany Lacombe, in Porn Power: Sex, Violence, and the Meaning of Images in 1980s Feminism, in“Bad Girls”/”Good Girls”: Women, Sex, and Power in the Nineties 188, 191-92 (Nan Bauer Maglin & Donna Marie Perry eds., 1996).
All three positions can be true — pornography can lead to harm, censorship can lead to harm, and some viewers are sophisticated. But not sophisticated enough to view the Federal Bureau of Prisons’ study. So you can download porn, but not data about its effects.