If, by the people's consensus, it's legal for said 18-year old to have sex with said 14-year old, exactly why would it be illegal for said 18-year old to look at said 14-year old naked, in a photograph or otherwise[1]?
As to your second point, wiretapping laws already exist.
[1] I could actually see an argument along the lines of "the internet never forgets", "having nude photos of yourself online sucks", "14-year olds do stupid things and should be protected from themselves". However, it's not at all clear that destroying the 18-year old's life is the best way to "fix" this. (It's also quite possible to have different rules for supposedly private messages and public distribution.)
The law gets interpreted very strictly and very literally around this subject. In fact, there has actually been a case where a 15-year-old girl was arrested for taking nude photos of herself and sharing them with others via chatrooms. She was charged with trafficking in child pornography, which is somewhat understandable. But she was also charged with exploitation of a minor, which seems a bit silly in this case (unless she had a split personality doing the photography?).
> She was charged with trafficking in child pornography, which is somewhat understandable.
I'm not sure how. The intent (as I understand it) is to protect minors from predators and exploitation, not to give them a criminal record for their own actions - consider that the perpetrator and supposed victim are one and the same in this case. Had they charged others who viewed/shared the photos in the chatrooms, that would be understandable, even if they're minors themselves.
Whether she realized it or not, she became the initial vector for distribution of child pornography the second she shared the photos online. So there is a semi-reasonable argument to be made that she caused some degree of social harm in distributing the photos. I'm not sure which side of the fence I fall on, but at least I could entertain the argument with a straight face.
The exploitation charge, on the other hand, was patently ludicrous.
> So there is a semi-reasonable argument to be made that she caused some degree of social harm in distributing the photos.
Entertaining that argument, the harm though would be to herself. Why should she be essentially doubly punished with membership to the sex offender's list and a criminal record?
As to your second point, wiretapping laws already exist.
[1] I could actually see an argument along the lines of "the internet never forgets", "having nude photos of yourself online sucks", "14-year olds do stupid things and should be protected from themselves". However, it's not at all clear that destroying the 18-year old's life is the best way to "fix" this. (It's also quite possible to have different rules for supposedly private messages and public distribution.)