Ted Bundy tried to use pornography as an excuse of why he hacked an whacked his victims to death.  Got news for you, Stevenson, Bundy didn't sexually abuse his victims before murdering them, he did it for the sheer pleasure of killing them because they reminded him of his ex-girlfriend.  Nobody, not even Bundy, can explain why he or any other serial killer does what they do.  Gotta admit though, pornography doesn't encourage good behavior; not for the seeker or the gals spread eagle.