The Carnival Corporation said a social engineering attack enabled hackers to access sensitive information, such as passengers' dates of birth and passport numbers.
In what is possibly one of the worst data breaches in history, hackers may have stolen the Social Security numbers of every American.
AT&T blamed an "illegal download" on a third-party cloud platform that it learned about in April - just as the company was grappling with an unrelated major data leak.
Live Nation, the parent company of Ticketmaster, revealed Friday evening that it was the victim of a cyber attack that compromised user data.
Xfinity concluded on Dec. 6 that usernames and passwords for some customers were stolen along with names, contact information and other user data.
Experts say it's hard to predict why Hayward was targeted, but how quickly the city was able to get back online demonstrates what went right: that the city was prepared, its system was designed for the worst case scenario, and that it likely had a strong backup system.