The rights you have in the workplace can be a gray area, and the information you might get from family and friends isn't always correct. For example, you don't always have a right to free speech in the workplace, and you can be fired for saying certain things. In most cases, individuals who work for private companies are only protected when it comes to speech that is protected under another type of law — for example, what you say might be protected under a whistleblower law.
Surely you're protected when you speak out against what you perceive as wrong-doing in the workplace, right? Not always. You can lose your job for speaking out against actions that aren't covered by specific laws. If you speak out against discrimination, illegal financial activity or health concerns, then these might be covered under federal or state laws.