I would say where there is a demand, there is a supply. As long as people wish to come to Canada, pay the money, and crooks like immigration consultants take advantage of the money, nobody will report it. Honest people will never report, fearing that it might affect their application or their future negatively.
They just take it as it goes, and pay the money. It is very hard to report. I would respectfully like to recommend that there be some sort of promise of immunity for international workers or students, so that if they report, their applications won't be affected by doing so. This would certainly help catch the fraudsters.