Openly disclosing the threat because it is the kind of behavior that falls within the bounds of social norms pretty much makes it ok. It is harder to blackmail

Openly disclosing the threat because it is the kind of behavior that falls within the bounds of social norms pretty much makes it ok. It is harder to blackmail people out in the open. In any case, I think the line is marginally less blurry when you consider the blackmailer's intentionally maintained ability to do harm with the unreleased information. The blackmailer must have information which is known to be harmful to reveal, and they use the threat of that harm to coerce something out of the harmed party. It's not really about secrets per se, but secrets which can be leveraged to do harm.