Can an Inland Revenue employee find out someones earnings?
Yes, it is possible. Just like non-gov’t types, most organizations/business has rules to protect private information of their clients but in reality the average employee tend to disregard those rules and treat sensitive information haphazardly. They would look at sensitive information that they have no legimative reason to be looking at just to satisfy their casual curiosity etc. Most of this activity is not born out of deliberate malfeasance and maliciousness but ignorance and poor governance. It happens even in the most highly regarded institutions, its human nature.