Apple joins major corporations like Time Warner, Comcast and News Corp. as a porn distributor.
Those companies sell pornography through their cable and satellite affiliates. Apple gives it way (for now) through its podcasting feature on iTunes. And, unlike those television services mentioned above, Apple's sultry podcasts go unlabeled according to iPodLounge.com. I'm sure Apple will catch on and either start labeling them (preferred and probably most likely) or try to filter them (not preferred and tough to police).
P.S. Yes, "porn" is intentionally misspelled in the title.