A federal judge in the Northern District of California delivered a blow to a potential class action lawsuit against Google over its ad auction practices. The lawsuit, which allegedly involved tens of millions of Google account holders, claimed Google’s practices in its real-time bidding (RTB) auctions violated users’ privacy rights. But U.S. District Judge Yvonne Gonzalez Rogers declined to certify the class of consumers, pointing to deficiencies in the plaintiffs’ proposed class definition.