4 Verizon
In some cases, data breaches are the result of human error rather than a malicious attack. One such example is the Verizon breach from July 2017. In that case, sensitive customer information was left accessible online for around nine days before being found and secured. The cause? A mistakenly configured setting on a cloud server.
That information included phone numbers, names and PIN codes for over six million Verizon customers. Verizon later told CNN that “no loss or theft of customer information occurred.” Despite that, the telecom giant recommended that users change or update their PIN codes, so there’s a chance that some of the data was accessed.