tiltjlp - a protocol could simply say that Private Messages are never to be publicised under any circumstances except by the author themselves or with the author's permission. This would be the policy, and would satisfy your point.

I also agree that if there is the possibility of any exceptions being made the name 'private' message should be changed - as it is not an appropriate description - how can something be a private message if someone else has the right to publish it? This does not make sense.