Houghton Mifflin Harcourt (HMH) Data Breach (2025)

"There is clearly a lot of data to go through, and this is just a preliminary report. DataBreaches also asked ShinyHunters whether all of these victims had been contacted previously with ransom demands or if some might first be finding out today. He replied that all had been notified: All of them have been contacted long ago, they saw the email because I saw them download the samples multiple times. Most of them chose to not disclose and ignore. It will now literally be leaked on the deadline if they do not engage before then."