An article in Slate called “How the Web Prevents Rape” discussed what the data shows when you look at levels of rape in different parts of the country as their access to internet porn increased, and also the levels of violent crime when violent movies are released in theatres.
The bottom line on these experiments is, “More Net access, less rape.” A 10 percent increase in Net access yields about a 7.3 percent decrease in reported rapes. States that adopted the Internet quickly saw the biggest declines. And, according to Clemson professor Todd Kendall, the effects remain even after you control for all of the obvious confounding variables, such as alcohol consumption, police presence, poverty and unemployment rates, population density, and so forth.
I think this bucks the conventional wisdom. Researchers argue that previous experiments on the effects of pornography on whether a man was likely to have misogynistic way were limited by the environments of the lab.
The data is also interesting on violent crime, implying that people who are likely to be violent are probably off watching a movie instead of causing trouble, if a suitable movie is in the threatre. But the effect seems to last the night.