This character blackmails someone.

Blackmail is the act of threatening to reveal substantially true information about a person to the public, a family member, or associates unless a demand is met. This information is usually of an embarrassing, socially damaging, and/or incriminating nature. As the information is substantially true, the act of revealing the information may not be criminal in its own right nor amount to a civil law defamation; it is the making of demands in exchange for withholding the information that is often considered a crime.