What you practised
- Open the Share box of a folder, and read who has access.
- Find the risks: student accounts, personal addresses outside the school, and "Anyone with the link".
- Remove the access of a person in one step from the role menu.
- Set General access to Restricted, so that a link alone does not open the folder.
- Lock the share settings, so that editors cannot share the folder again.
Do this check on each folder with exam papers before the exam season. A Google Workspace admin can also set the sharing rules for the whole school in the Admin console, for example no sharing outside the school domain.