Yahoo's board decided not to award CEO Marissa Mayer a cash bonus "that was otherwise expected to be paid to her" due to the data theft security breach, according to a company filing on Wednesday. The Yahoo hack, which happened in August 2013 but wasn't reported until September 2016, is considered "the worst hack in history" (Hemu Nigam, CEO of online security consultancy SSP Blue). This latest news reminds executives that they must be aware of and mitigate the risk for cybersecurity breaches, or face financial consequences.