Law360, New York (March 29, 2013, 11:57 AM EDT) -- On March 20, 2013, the United States District Court for the District of Maine denied a motion brought by plaintiffs in In re Hannaford Brothers Company Data Security Breach Litigation that would have allowed the suit to proceed as a class action. The decision, which concluded that plaintiffs had failed to meet the predominance requirement of Federal Rule of Civil Procedure 23(b)(3), demonstrates the difficulty of certifying a class in the data breach context, where claims often turn on individual issues of causation and damages. Perhaps most significantly, the decision signals that in order for data breach plaintiffs to meet their burden as to predominance, they must first obtain a supporting opinion from an expert....