It is not about finding breasts shocking.
It is about finding pictures of them in a newspaper inappropriate.
When my child sees a topless woman on a beach getting a tan, or a mother breastfeeding in public I do not mind at all.
If my child comes across men sniggering over page 3 and speaking of the young woman they are looking at as if she were a piece of meat, as I did as a child, I will not be happy. If these pictures make her feel less confident about her body and the place her gender has in society, I will not be happy.
Of course there is worse in online pornography. That is a separate issue. The issue with page 3 is not erroneously believing it to be hardcore pornography of the most extreme kind, the issue, for me, is the message conveyed by a young woman's body being treated as a commodity in a mainstream newspaper. It normalises it. It condones women being judged as a pair of breasts on legs not a person. Having to search for something online does not give out the same message of 'this is a normal thing most men do' as having it in the Sun.
I have been sexually assaulted, twice, because two men saw me as something they could use, not a full human with rights. The more these young men with bad attitudes are supported in the belief that women are less important than the entertainment value of their bodies, the worse this attitude will get, I fear.