Yahoo—Yahoo suffered data breaches affecting all 3 billion user accounts, board found 'failures in communication and management'
Yahoo disclosed two massive data breaches (2013 and 2014) affecting all 3 billion user accounts. Yahoo's board found that the 2014 breach 'was not properly investigated' and cited 'failures in communication, management, inquiry and internal reporting.' The breaches significantly reduced Yahoo's acquisition price by Verizon.
Scoring Impact
| Topic | Direction | Relevance | Contribution |
|---|---|---|---|
| Corporate Governance | -against | primary | -1.00 |
| User Privacy | -against | primary | -1.00 |
| Overall incident score = | -0.644 | ||
Score = avg(topic contributions) × significance (critical ×2) × confidence (0.64)× agency (negligent ×0.5)
Evidence (2 signals)
NPR reported Yahoo revised breach total to all 3 billion user accounts
NPR reported in October 2017 that Yahoo updated its 2013 data breach estimate from 1 billion to all 3 billion accounts that existed at the time, making it the largest data breach in history.
CNBC reported Yahoo CEO knew about data breach months before disclosure
CNBC reported that Yahoo CEO Marissa Mayer knew about the data breach investigation since July 2016, but the company withheld information from investors, regulators, and acquirer Verizon until September 2016.