I'm a little late to the game on this case (Gatto v. United Airlines). It's about a personal injury case in which the defendant sought discovery of a the plaintiff's Facebook page. Yadda, yadda, yadda, plaintiff deletes his Facebook page and the court sanctions the plaintiff.
But here's the part I like:
While Facebook did respond to the subpoena served upon it, Facebook objected to providing certain information related to Plaintiff's account due to concerns regarding the Federal Stored Communications Act. Facebook instead recommended that the account holder download the entire contents of the account as an alternative method for obtaining the information. Defendants allege that this issue was discussed with the Court during a telephone status conference on January 6, 2012, where Plaintiff's counsel advised that he would be willing to download the account information and provide a copy to the parties. Defendants allegedly agreed to Plaintiff's proposal, with the condition that Plaintiff would also provide a certification that the data was not modified or edited since the December 1, 2011 settlement conference.
So, if you want discovery of the contents of a litigant's Facebook account, don't mess around with subpoenas to Facebook and don't demand Facebook passwords. Instead, lay the proper foundation (i.e., establish that there exists information on a litigant's Facebook page that is likely to lead to the discovery of admissible evidence) and make a download your information request.