Interesting how the forum seems divided down cultural lines over this question, most of the US posters with one or two exceptions, seem to feel that it's a big no-no to repeat an abusive communication from a virtual stranger over the internet while most of the UK commentators here feel no such compunction to keep it a secret that someone sends out abusive messages.
Don't hide behind "private" messages to talk shit to people and then expect THEM to keep it a secret for you is my attitude. Nasty and aggressive messages don't deserve to be treated with respect.
Perhaps if people didn't feel so safe and secure here about sending strangers personal nasty messages and those messages being kept a secret, it wouldn't happen as frequently as it would appear to do here?