Getting one thing out of the way: No, I have no interest in blackmailing anybody. And I am not at any greater risk of being blackmailed than most people.
But inquiring minds do want to know.
Is blackmail always illegal? Would it be a civil case, a criminal case, or both?
Suppose I was blackmailed by Mr X. Mr X says pay up or he’ll tell somebody that I did Illegal Thing Y. If I pressed charges against Mr X, would I have to prove that I did not do Illegal Thing Y for the blackmail charges to stick?
If I did press charges against Mr X, would I be investigated for Illegal Thing Y? Is there any protection against these charges?
If Mr X were threatening to reveal something that wasn’t illegal, but Embarrassing At Work, would I be able to press charges against Mr X without having this revealed?
Like I said, I’m asking out of curiosity rather than worry. And I’m not out to ruin anybody else, either.
First, definition: blackmail is in many state codes used interchangably with statutory extortion; in other state codes and in federal law, blackmail is specifically the extortionate crime threatening to inform (or failing to inform in return for consideration) of a violation of state law or U.S. law, respectively, for money or valuables. These codes vary a great deal in wording.
Blackmail in either sense is always illegal by definition. It’s a threatening demand made without justification. If it isn’t an illegal demand, it isn’t blackmail, it’s just a pressure tactic.
Generaly, no. His crime is separate from yours.
Yes, you would. No, there isn’t. However, if you are a small fry and the blackmailer is a big fish, a prosecutor may be willing to cut a deal with you in return for your cooperation.
Extortion in the broader sense doesn’t necessarily have to concern exposing illegal activity. Say someone threatened to reveal embarassing private matters if you didn’t pay up, or burn down your business. This would be extortion of blackmail under most state codes, depending on the wording used.