It is the things that are said that may cross over the legal line, not the fact that something was posted. In other words, the content is actionable in my opinion.<quoted text>
Keep in mind that "anonymity" only goes so far.
At least the employee you talk about has the balls to say things about people under his real name.
This could become a dicey issue for the author, mayor, and his boss the fire chief. The next move is up to those targeted by his Facebook posting.
A former city employee resigned over something not too different. The precedent has been set, perhaps. This is not a good situation for some.