Since the 1970s, many women's groups and feminist writers have criticized pornography, especially hardcore pornography, arguing that such pornography degrades and humiliates women. Some psychologists who have talked with many people in jail for violent sex crimes believe that pornographic depictions of violent sex often make people less caring about other people's feelings, which might make them more likely to commit rape and other sex crimes. Many pedophiles, who sexually assault children, also have collections of child pornography. 