Who knew they had so many users? Yahoo disclosed today that a 2013 hack compromised 1 billion accounts — twice as many as the 2014 hack reported in September — including 150,000 U.S. government and military employees. The potential national security threat could also complicate the internet pioneer’s $4.8 billion deal to sell its core business to Verizon. The stolen data includes names, email addresses, phone numbers, birthdays and security questions and answers. Yahoo believes payment information is safe, but is still probing how hackers cracked its security.