I've worked on the data feeds for TWN in a large company's payroll system. If I remember right they don't just get how much money you made but the line by line check level data. Your pay data probably goes out to 14 different vendors on any given pay period. What amaze me about payroll was how accurate the data was on average, despite having wild amounts of new regulatory, healthcare, union, and pay program complexit…
I wonder if these people understand their value to an organization.