First, you must tell the mediator what you learned and how you feel. Call or write at once, making it clear in a non-accusatory way that you value your privacy and expect that it will be guarded. Give the mediator a chance to explain; occasionally, even the best of friends exaggerate a bit, or there could have been some kind of misunderstanding.

If, however, you become convinced that the mediator really did disclose details about the mediation, ask for a signed statement promising not to do so in the future. If the mediator does not cooperate in this, file a complaint with the organization that connected you with the mediator. If the mediator is a lawyer, you can also file a complaint with your state's licensing organization, usually the state bar association.