The numbers stored on the device belonged to former nursing students who attended the university before late 2006, said Armstrong spokesperson Francisco Duque. That was when the university stopped using Social Security numbers for student identification.
"It was to prevent this kind of thing," Duque said.
The use of the portable device to store confidential information was a violation of university policy, Duque said. While no one was disciplined, the violators of the policy - as well as all faculty and staff - will be provided additional training, Duque said.
All of the former students impacted have been notified, although letters did not go out immediately, Duque said.
A notification letter obtained by the Savannah Morning News is dated Nov. 24 - seven weeks after the incident was reported to university police.
The delay occurred because of the time it took to figure out what was on the device and who to contact, Duque said.
"It was not easy," he said. "There was a lot of information there."
The letter from Shelley Conroy, Dean of the College of Health Professions, recommends the former students place security freezes or fraud alerts on their credit reports to prevent their unauthorized release.
Despite the recommendation, school officials say they believe whoever stole the device did not do so to get the Social Security numbers, but wanted the device itself.
"It looks like a crime of opportunity," said Armstrong Police Chief Wayne Wilcox.
While the hard drive has not been recovered, some "people of interest" have been identified, Wilcox said.
The theft came after a week of reports of snack-food items such as granola bars and potato chips being taken, Wilcox said. It appears someone had obtained a key to the health professions building and gained access when it was closed, he said.
The school has since instituted improved safeguards to better secure such keys, he said.
Theft of confidential information is happening more frequently and getting more difficult to prevent in today's "connected" world, said Hans Klein, associate professor in the school of public policy at the Georgia Institute of Technology.
Klein cited the recent WikiLeaks publication of secret government files that had reportedly been downloaded onto a homemade music CD.
"They say all the WikiLeaks information was on one Lady Gaga CD," he said. "There is nothing to it."