Distinctions between criminal blackmail and journalism
Journalism: Obtain information that would be of interest to the public, and then make money writing things that it is believed the public should know about
Blackmail: Obtain information (whether involving embarrassing, criminal, or any any sort of thing), potentially including fabricated information that has some element of believability, for the purpose of using this to coerce the individual to a) refrain from particular activities, speech or viewpoints, b) perform a particular activity, engage in particular speech or promote a certain viewpoint. Specifically, for the purpose of coercing someone to do what they would not otherwise do, or to not do what they otherwise would do.
Journalism: The journalist interviews the source who has information which may be comprising to that individual but which deemed likely to be of general or specific interest to the public. In almost all cases the journalist retains the legal right of prerogative regarding revealing, or not revealing, this source.
Blackmail: The information having been obtain, it is made know to the individual by any means calculated to potentially have the desired coercive effect. No public interest case exists (although falsehoods regarding public interest may be promoted among those actively involved in perpetrating negative treatments intended to promote coerce-ability on the part of the target.
In short, journalists obtain information that is of interest to the public and they protect their sources. Whereas with blackmail false or true information is used in order to control an individual.
Not the same thing. However, it seems that some diversity of actors involved in blackmail-oriented activities have (with varying degrees of pretension involved) difficulties understanding the difference between the acts of a) obtaining information of interest to the public and protecting sources, and b) trying to assert domination over an individual.
Due to the existence of the common thread of “something that someone doesn’t want to be publicly known about them” (including potentially false things), it seems that some diversity of actors involved in blackmail hunting and other blackmail-directed activity have difficulties allowing themselves to take a moment and comprehend that journalism for public interest and blackmail people to control or perhaps enslave them are fundamentally different activities.