At least in Norway it's already public what everyone makes. I can look up the taxable salary information about anyone (so salary after deductions but it's probably ok close). Also, even without that, salary of public employees is part of the information you can request to view. I feel discussing salaries is quite common here. At work someone made a spreadsheet everyone fills their salary into if they want, experience…
The lesser form of abuse would be for a shop to loop up how wealthy a customer is for targeted advertising. But it can also be used to see whose kid is worth kidnapping, and everything in between, like refusing tenants with low salaries.