Most of the bank account records in question are from students who received direct deposit refund payouts from the university, Mauk told the Journal Star. Students typically receive refunds after dropping classes or receiving excess financial aid and scholarship money.

The content of Saturday's email concerned those on its receiving end.

"I don't care if someone knows I got a refund the last two semesters, but if they have my Social Security number, that is a different story,” said UNL sophomore Schuyler Sharp. "I hope the university will respond as they said they would: finding the mistakes and making them right again.”

Mauk referred to the group of 30,000 recipients as the university's "primary focus" and the higher priority among those possibly affected.

“From a financial risk perspective, bank account information is the most high-risk data that we’ve classified in the system,” Mauk said Saturday. “The next priority is personal information and Social Security numbers, and that’s what we’ll be working on throughout the weekend.”

He said credit card information tied to the schools' application processes was not compromised because the university system does not store that information in the system.