Rita Risser Chai replies:
It depends on how the employee became aware of your salary. If you told the employee your salary, then it doesn’t seem like you were treating your salary as private information, so you can’t complain if they don’t treat it as private. On the other hand, if they found out because part of their job is to handle this confidential information, then they would be in violation of company rules of confidentiality. This should be treated the same way other violations are handled. Presumably, most violations do not result in immediate termination. In any event, you should not be making the decision about discipline or termination, because you are emotionally involved in the situation. Your manager (with HR) should make the decision.
Information here is correct at the time it is posted. Case decisions cited here may be reversed. Please do not rely on this information without consulting an attorney first.