Yahoo
SIZE : 3 billion accounts DATE : October 2013 & October 2017
Don ’ t be fooled by the two dates , this is the same breach but reported on two separate occasions by victims Yahoo . The original attack , where Yahoo claimed hackers had compromised a billion , happened in 2013 but was only reported three years later while the internet giant was in negotiations with Verizon for a sale . Then Yahoo later came out and admitted the actual figure was closer to 3 billion compromised accounts . One of the original internet pioneers , and the most visited site on the web back in the day , Yahoo ’ s steady but relentless fall from grace saw it turn down the chance to buy Google ( US $ 2bn ) and Facebook ( US $ 1bn ) before finally being acquired by Verizon for US $ 4.5bn in 2017 – around a tenth of its value at the height of the dot . com bubble . cybermagazine . com 121