I think it is easiest to google search for a porn video than any other thing. What I notice is that whenever a sexual criminal is caught and when Police search for his belongings, almost every time Police find a pen drive of very high storage full of pornography or the criminal's computer/s is/are filled with excessive porn videos. One more important thing to notice is that often the victims quote that the criminal/s made them to watch (many a times the victims are not adult) those porn videos and to mimic what's happening in it.
This question here claims that sexual offenses have gone down with easy availability of porn, but that's the case (if true at all) in developed nations where the punishment for sexual offenses are very strict, but in developing countries where Police and Courts are over-busy with the matters of Governmental corruptions and crimes sexual offenses many a times go unnoticed.
I read somewhere that we feel excited and aroused when we see an unclad body's image because our brains tell us that it's time for reproduction and the person in the image is a right candidate for the reproduction (we are evolved like that). But in the pornographic videos things are different, and they cause people to go mad and imitate the acts done in the video.
All right, let's have a look at some so called notable claims: In this link we find a governmental minister saying:
that pornography is incitement to rape
Pornography is banned in China, and this link says
Pornography is strictly forbidden in China. Those who produce, disseminate, or sell “obscene materials” could be jailed for life, according to the country’s criminal law.
So, you see production of pornography is a crime in China. Not only China but other countries too see Pornography as crime, Philippines's ISPs banned pornography by saying
the sites have been blocked because of anti-child-pornography laws.
Rich countries know that they, ISPs and porn industries make a lot of money by pornographic sites so they don't completely ban it (just like government realized that imposing high tax on alcoholic beverages would benefit them more than prohibiting the alcohol) but they know and when the truth.