How does imogene herdman blackmail her classmates?

Imogene Herdman blackmails her classmates by leveraging their secrets and vulnerabilities against them. She uses her knowledge of their personal issues to manipulate them into doing what she wants, creating an atmosphere of fear and intimidation. This tactic effectively allows her to maintain control over her peers, as they are unwilling to confront her due to the potential exposure of their own secrets.