A California federal court ruled that nonpublic Facebook communications and content is protected by the Stored Communications Act and cannot be access by a civil subpoena. The ruling gives added privacy protection to Facebook users who set privacy settings to not share with the public. The question settled by the court arose from a copyright dispute regarding artwork. The court left the question to a lower court of whether the content was publicly available or not.
Can You Subpoena Someone's Facebook Page in a Civil Case? [Revisited], by Venkat Balasubramani, Spamnotes,