As requested by Packers.
As I explained, my "disagree" vote on Allan's claim was due to the presence of the word "peddling". While I agree that it's highly unethical for an adult to advertise or knowingly sell pornography to a child, I don't see an issue with children obtaining pornography in a context where an adult isn't using it to manipulate them.
I mean, hell, I'm sure I wasn't the only teenager whose first instinct upon discovering Usenet was to search for porn, and I turned out OK. Even though Usenet lacks even a silly "I am over 18" check-box, I don't see anything unethical with either the existence of alt.binaries.pictures.erotica.* or with the vast majority of people who post pictures there.
Discussion (1)
The ethical matters would be in the hands of the adults who could have prevented access to pornography. For instance, by installing filtering software on a computer, or locking up their own pornography stashes.