The California Supreme Court has taken up a case that could determine if, how and when Facebook must turn over private user information about third-party witnesses in criminal cases.

California's high court announced Friday that it agreed to review Facebook v. Superior Court—a criminal defendants' appeal of a Fourth District Court of Appeal decision that found Facebook couldn't be compelled by a criminal defendant to hand over private posts and user information.

Lawyers in the underlying criminal case for Lance Touchstone, who is awaiting trial on an attempted murder charge, are seeking access to the Facebook profile of a man Touchstone is accused of shooting. Touchstone's lawyers want to probe the private material for potentially exculpatory evidence since the victim posted publicly on Facebook about drug use, guns and his desire to rob and shoot people.

Touchstone's lawyers have said the case illustrates the imbalance between access that criminal defendants and prosecutors have to information from social media platforms. Prosecutors who've shown probable cause and obtained a warrant can force social media companies such as Facebook to hand over information users designate private. But Facebook and other electronic communication services are expressly prohibited from handing over private user communications to others under the federal Stored Communications Act.

At the lower appellate court, Touchstone's lawyers argued the SCA infringed upon his constitutional rights to a fair trial and due process. But the Fifth District pointed out his lawyers could still seek a court order from the trial judge to force the victim to consent to Facebook's production of his private communications for in camera review.

In taking up Touchstone's appeal, the California Supreme Court provided an exceptionally long list of questions to the parties. Court policy explicitly states that its preliminary case statements don't “define the specific issues that will be addressed by the court.” But the court's questions point to an inherent tension between a state court's authority to control litigation before it and ensure fair proceedings and the federal digital privacy law.

Facebook's lawyer, James Snell of Perkins Coie, didn't immediately respond to an email message seeking comment. Neither did Touchstone's lead lawyer, Katherine Tesch at the Office of the Alternate Public Defender in San Diego.