A federal judge has granted approval for tens of millions of Apple customers to proceed with a class action lawsuit, accusing the tech giant of monopolizing the iPhone app market. The case, initially declined for class action certification, has been allowed to move forward after being narrowed down. The consumers' attorney expressed satisfaction with the decision and estimated that the class has suffered 'billions of dollars in damages.' The ruling marks another legal challenge for Apple, which has been facing increased scrutiny over its App Store policies, and the case is overseen by U.S. District Judge Yvonne Gonzalez Rogers. The case is In re Apple iPhone Antitrust Litigation, U.S. District Court, Northern District of California.