Four employees of the Student Loans Company have been fired after threatening colleagues on Facebook, as well as posting "derogatory" marks about students.
A Freedom of Information request found that staff members posted the offensive comments about student customers, a manager and the company, as well as comments which "threatened the health and safety of fellow employees".
The Student Loans Company said all four were dismissed after disciplinary action was taken.
Mhairi Docherty, the head of human resources at the company, said: "Employees of the Student Loans Company are required to follow a number of corporate HR policies and guidelines.
"Our staff are expected to behave and communicate with other employees, customers and the wider public - whether through social media or any other communications channels - in a professional and responsible manner.
"SLC does not tolerate abusive behaviour or threatening behaviour and we are committed to dealing robustly and appropriately with any cases of related misconduct to protect our customers and staff."
Steven George-Hilley, from the think-tank Parliament Street, who made the request about social media misuse over the last five years, said: "These incidents suggest it may be time for extra lessons in social media etiquette at the Student Loans Company.
"With correct training and policies in place, staff can use social networking sites like Facebook to share important application information and deliver interactive services to students."