An appeals court revived a lawsuit against the anonymous messaging service Yolo, which allegedly broke a promise to unmask bullies on the app. In a ruling issued Thursday, the Ninth Circuit Court of Appeals said Section 230 of the Communications Decency Act shouldn’t block a claim that Yolo misrepresented its terms of service, overruling a lower court decision. But it determined the app can’t be held liable for alleged design defects that allowed harassment...