Yahoo faces questions after hack of half a billion accounts

The company has confirmed that the breach took place in 2014 but its statement left pressing questions unanswered

Yahoo's admission that the personal data of half a billion users has been stolen by "state-sponsored" hackers leaves pressing questions unanswered, according to security researchers.

Details, including names, email addresses, phone numbers and security questions were taken from the company's network in late 2014. Passwords were also taken, but in a "hashed" form, which prevents them from being immediately re-used, and the company believes that financial information held with it remains safe.