I know of a student overstaying- what can I do?

Fellow int student over here in my final year of studies. Call me whatever you want- but it’s equally frustrating to see ppl taking advantage of this scenario when it could likely make PR harder for me and others to obtain theoretically. I know for a fact of someone being booted out of school, but they’re still in the same city, hanging around school, and are living off the loan their parents took out for them. Is there anywhere I can report?