Instead of caveat emptor--let the buyer beware, it has now become caveat posteri: let the poster beware. Several court rulings have said that a Facebook page falls within the scope of discovery if the page contradicts statements made in discovery or testimony. There is currently no record of a court recognizing a general privacy privilege regarding Facebook information. Even making a Facebook page "private" does not keep it from being discoverable in a legal matter since Facebook posts are still shared with others online.
In Largent v. Reed, Judge Richard J. Walsh in Franklin County, Pennsylvania ordered the plaintiff to give her Facebook user name and password to the defendant. Mr. and Mrs. Largent claimed that Jessica (Reed) Rosko caused the motor vehicle accident that severely injured both of them. Mrs. Largent posted about going to the gym on her Facebook page but gave testimony that she had to walk with a cane. The discrepancy caused a questioning of the severity of her injuries and gave defense counsel the relevancy standard they needed to comb through the rest of Largent's Facebook page.
With social networking sites, it is easy to keep up with family and friends and connect with others with similar interests, but the down side is this: social networks collect larger amounts of sensitive personal information than traditional consumer data collecting companies and distribute it much more quickly. For example, Facebook can track other websites that users visit--even when users are not logged in to Facebook. Tracking occurs through the "like" and "recommendations" buttons on web sites. When these buttons are clicked, the date and time users visited the web site and the IP address is logged. This data logging coupled with the fact that Facebook and other social networking sites have access to everyone's information even if a page is made private has alarmed many. To make matters worse, U.S. law is not strong when it comes to protections on social networking sites. What can you do?
How to Use Facebook Privacy Settings