If you are thinking about all your problems with your employer, and want to tell the world- or, tell Facebook, listservs, and/or public message boards- you should think twice and count to ten before posting.
It is understandable to feel highly frustrated by an employer who has underpaid you, harassed you, fired you, or otherwise treated you unfairly.
But don't let your frustration cause you to make careless postings of public information about all the hurt and anger you feel, and all the details and opinions on your mind. Once you post specific identifying information (employer's name) and alleged conduct, you are crossing into a threshold where negative consequences can occur.
When people are hurt, they tend to communicate in an emotional, and often counterproductive, manner. An employee posting negative information about an employer could cross the line, and post something that the employer would claim is false or damaging to the employer's reputation or business.
In some instances, an employer could bring a lawsuit for defamation against the poster.
There is no use for fightin' words in the legal world: the facts are what matter, e.g. facts about the worker's termination.
And the facts only matter if they are communicated to the right place: to an attorney, to a legal decision-maker, or to someone else who can help.
Information that is posted on messages boards and the like is posted to everyone- to some people who could possibly help you, but also to some who could possibly hurt you.
If the employer reads negative information and details that you post about the employer, the employer could decide to make an issue, or a lawsuit, out of your post. The legal focus could shift from the core issue (unpaid wages, termination, etc.) to the issue of the comments you posted about the employer, and whether they were necessary, professional, or true.
Yes, truth is a defense to a defamation claim. But no defense is guaranteed. And even if you had a winning defense to a defamation claim, you would still have to pay for defending yourself in court, in all likelihood, if a lawsuit were filed. The best plan is to avoid the risk altogether, and not make negative message board posts in the first place.
If you want to fight an employer, make sure the fight is in the right forum (e.g. communicated via an attorney or legal proceeding, not via a message board), and fight with the facts rather than emotional adjectives or opinions. If a party is making negative comments on message boards, that party runs the risk that in later legal proceedings the party may be viewed as unprofessional or not credible, even if they are in the right.