Either expose his identity or do not expose his identity. Saying they will expose his identity or not based on his future on-line behavior violates all sorts of journalism standards -- and can only be defined as blackmail.
What if FOX News did the same think to you on ET. They hunted down your real identity, called you up, made you apologize for your many previous offensive posts (in their eyes), and then said that they would release your name publicly if your future behavior on ET did not meet their undefined standards for being non-offensive. What would you call that?
The correct term is blackmail.