The two upperclassmen, from Hinsdale Central School in Chicago, held the information "for months", but according to the school have not done anything with it.
A letter sent home by the principal on Wednesday confirmed the data had been accessed and suggests that it was taken "to demonstrate that they could gather the data than on actually using the Social Security numbers."
"In a really weird way, they are doing the system a favor because they are showing the system needs [help]," said one anonymous student in an interview with the Chicago Sun-Times. "I don't want anyone getting my Social Security number, so I'm glad these guys got it first, before a criminal went in and messed with our Social Security numbers."
The students are expected to be disciplined in the next few weeks.
The news arrives in a year of data breaches at educational establishments. In early April SC reported 7,000 students at the University of California in San Francisco potentially had personal information stolen by a hacker.
In late March 5,000 faced the same situation in the University of Nevada, Las Vegas.