I hope the answer to this question is no. Nearly twenty years ago, Robert Redford starred in a movie about hackers. One scene in the movie shows them decrypting the phrase "No more secrets." The recent Pennsylvania case Largent v. Reed (Pa. Common Pleas Nov. 8, 2011) proves this is a reality of the Internet Age. In Largent, the defendant asked the judge for access to the plaintiff’s Facebook account so he could prove that she was exaggerating her injuries. The judge ruled that plaintiff’s access to Facebook was not protected under various statutes and granted defendant 21 days of access to plaintiff’s account.
Although this is just one judge, it is likely a sign of things to come. With this in mind, it would be good to apply Rule 24 "Avoid confidential info" of PC Mag’s golden rules of email to Facebook and all social media. We already know that "nothing is private on the internet". The internet is amazing, but privacy has become one of the casualties of attaching everything including our personal lives and appliances (everything but the kitchen sink) to the internet.
If you are a plaintiff, be aware that even if a private investigator is not following you, your private life will likely be uncovered if you decide you pursue your claim.