https://www.recode.net/2017/11/7/16619312/senate-commerce-committee-yahoo-marissa-mayer-equifax-data-security >Senate lawmakers quietly subpoenaed former Yahoo CEO Marissa Mayer in October in order to compel her to testify before a key committee that’s investigating a 2013 security breach at the tech giant that has affected three billion of its users. >Initially, Mayer’s representatives declined to make her available to appear before the powerful Senate Commerce Committee, which is set to convene a hearing on Tuesday that explores the attack on Yahoo as well as a separate, later 2017 incident at credit-monitoring agency Equifax, which affected more than 145 million Americans.