Thinking about private and public again...

The case in question is a woman who was made redundant and was offered a large compensation package.  As usual the offer included a non-disclosure clause (family is ok, public is not, advise from friends who are discrete probably acceptable).  Therefore would it be acceptable to post on twitter and Facebook as these are closed (not public) networks.  However if someone enable the information to spread outside your network it therefore becomes public.

Therefore are we moving from private to public as being defined as when someone retweets your tweet!