Evil people love privacy. It allows them to commit their atrocities in secret, and to keep a sparkling public image. That image is paramount for them. As long as people look good, they don't have to do anything. In fact, the only thing that can guarantee them to leap into action is threatening their image. And here we have the power of public shame.
By highlighting in a public forum the evil things that people do, you smear that image. And from here, some will definitely happen. It could be positive (forcing them to fix their problems), or it could be negative, (forcing them to smear your reputation and then crush you like an ant). That largely comes down to their power levels, knowledge, and confidence.
Regardless, public shame is a powerful tool. As with all powerful tools, it can be used either to create or to destroy, but it is guaranteed to change things.