Blackmail is a law which forbids the possessor of some information from offering to sell it to the subject of the information. The possessor can sell it to anyone else in the world, but cannot offer to the subject.

If I had an affair with a celebrity, I can start a bidding war for my story between all the movies studios, television studios, and publishing houses. That's legal. If I invite the celebrity to bid, then I've committed a crime.

I've always found it hard to justify blackmail laws.

What you describe isn’t blackmail. Blackmail is offering the celebrity the chance to keep you from offering the story to the others, in exchange for a fee.

If you actually had a setup as you described, all of the news outlets would publish the facts of your story, without paying you anything, because facts aren’t protected by copyright. The only thing you could sell would be an exclusive interview.

So it's an ordering problem? It's only blackmail if I offer to sell my silence before making offers to other parties? So if I have an offer from a movie studio for the rights to my story and then allow the celebrity to make a counter-offer, that's not blackmail?

When I said publishing house I meant book publishers like Penguin Random House. I don't know where news outlets come into it.

You’re not offering the same thing to the publisher and the celebrity. To the publisher, you’re offering your version of certain currently unknown events that they may be interested in publishing. You’ll need to disclose the basic facts first before they will know if they even want to buy. To the celebrity, you’re offering the promise not to disclose even those basic facts to anyone, even to explain what it is you’re offering to other parties.

Whether the medium is a book or a newspaper or a website is legally immaterial. Thinking about the information as news is just useful because no one owns the facts, only their particular descriptions of them.

Weird, i always found it hard to justify the legality of either that type of bidding war or the operations and structure of an organisation that would participate it one.

I think blackmail is obviously wrong as is sensationalism and appealing to base desires over informing people. i am not sure where laws should apply, but these appear to be important levers in the control of our society we should pay special attention to due to their ability to enable and empower the unscrupulous. If we dont have laws to govern these thing we must accept the responsibility of society to educate everyone to a high standard (as an independent thinker, more than a rule follower) to mitigate the severe risk in this area.

Luckily extortion is illegal, and a venn diagram of the two is quite nearly a circle.