Legal Note

In a recent episode of Lost, Miles finally meets Ben and asks for $3.2 million. In return, rather than tell his superiors where Ben is, he'll tell them Ben is already dead.

Ben: You've arranged this meeting so you can blackmail me?

Miles: It's extortion if you want to get technical.

Extortion is unlawfully demanding something (usually money) through threat or intimidation (which tells us something about Miles' people, I guess). Blackmail is considered a form of extortion. It's extorting money by promising not to reveal some negative information (often something illegal, which doesn't seem to apply here).

Anyway, blackmail sounds to me like a fair description of what Miles is doing. You're already asking for a lot of money, Miles. No need to insult the man.