[yuuuuy]

Payroll companies (ADP etc)

Background check companies that do employment reference verification checks for employers

All three credit reporting companies have employment history products. So for example if your rental application includes your current and/or past employers, those will end up permanently with the credit reporting agency.

Plus others. Basically anyone that gets your employment info will sell it since as far as I'm aware it is not protected in the same way your credit history is.