Columbia (MO) - More than 22,000 students are affected by a hacker's entry into the University of Missouri's computer database, an announcement made even more disturbing by the fact that the same thing happened at the school just a few months ago.

Students were notified of the breach yesterday, in which names and social security numbers of a reported 22,396 people were stolen. According to an official security bulletin, those affected are people who were UM employees during 2004 and were also either students of alumni. Reportedly, the data was on the university server in a less secured environment for an internal report and was never removed.

"The University has been and will continue to work diligently to secure confidential data held in its computer systems. We are also working closely with law enforcement in our investigation of this event," said the university in an online statement.

It's been a tough year for UM's IT department. In January, outdated safeguards on the college site allowed a hacker to gain personal information of students, though it was on a smaller scale than the more recent attack.