That is the problem. No one "uses" Equifax. Credit Bureaus gather information from credit card companies, utilities and any other billers they can find that show payment history. They also try to capture your loans, and debt. Whenever you provide personal information for a transaction and it states in the fine print they can share with 3rd parties for the purposes of credit they are really sending it to companies like Equifax and Trans Union. They know a surprising amount about you.

What is terrible is the lack of transparency and lack of control consumers have over what is in the data. Particularly if it is wrong.

In Canada is illegal to "require" a SIN to be given for a transaction unless it is related to income (e.g. to open a bank account, investment, employment, etc.). I never give out my SIN or driver's license. Credit card numbers are okay because you are not liable for fraudulent charges. Never give out your PIN.