How are things being dealt with on a legal stand point when it comes to things like facebook, and publicly show private messages

Once you send an email, or a text, or post to a friend, you no longer have any expectation of privacy concerning what you sent (assuming the recipient did not expressly to maintain communications in confidence). The recipient is free to forward the communication as s/he wishes. Please see the post at the link provided below.

There is no broad scope protection against publication on the internet. It sounds like the issue you are dealing with specifically is an issue of possible libel -- the published writing of untrue statements that have the tendency to injure the subject of the statements. Take a look at California Civil Code sections 44, 45a, and 46. If you believe that you've been the victim of slander or libel, you should speak to an attorney to determine whether a lawsuit makes sense.

The internet is a powerful resource and informational tool. Like most things, there are good and bad aspects and as is almost always the case, there are abuses - sometimes intentional, sometimes not. Libel and slander are really just sub parts of overall defamation. It is also important to determine, based on facts: level / rights and expectation of privacy. Each has requirements, defenses and remedies. If you have a specific question, best to consult local attorney in field of practice.