Don't have the source offhand, but I remember reading about it (remember Bundy was a very, very slick psychopath who was very good at manipulating people and telling them what they want)...
IIRC The stuff about Bundy and porn was the result of some fundivangelist minister interviewing Bundy and Bundy telling the minister what he wanted to hear.
Thanks. That's a good starting point to research it myself.