I personally don't give a shit if everyone prints out the contents of their pm folders. I've never seen any inherent quality of pm's which make them immune from public disclosure.
One must choose whether or not one wishes to do so.
But, I can certainly see how public disclosure of a confidential report would be breach of privacy.
People report posts with the assumption that their report will be confidential. It's true that no promise of confidentiality is stated on the report page, but still, it's almost a given.
But, if that confidentiality doesn't exist, then they may well choose not to use the report function in the future.
It's up to the mods, I suppose, whether they want to encourage or discourage the use of the report function.
Personally, I think the report function is for pussies. Except in the case of spam.