WASHINGTON (Reuters) - The chairman of the U.S. Senate Commerce Committee said on Tuesday he plans to hold a hearing later this month over massive data breaches at Equifax Inc (EFX.N) and Yahoo, which is now owned by Verizon Communications Inc (VZ.N). Senator John Thune said he will ask witnesses from the two firms whether “new information has revealed steps they should have taken earlier, and whether there is potentially more bad news to come.”  Yahoo disclosed late Tuesday that a 2013 data breach impacted all 3 billion of its accounts, compared with an estimate of more than 1 billion disclosed in December. Equifax said on Monday that a data breach impacted as many as 145.5 million U.S. consumers, 2.5 million more than announced earlier this month.  
Senate panel to hold hearing on Yahoo, Equifax breaches