Who are the gatekeepers of media?

Imagine a news world where anyone could post any story they wanted to mass audiences, without being given their position, or without third party approval or accredidation? Thanks to the gatekeepers of media, this will never happen. The gatekeepers of media are the individuals who decide where and when certain stories are aired or printed. Whether they are appointed editors, supervisors, or journalists, they have complete control over the stories researched and published. They have significant ability to influence the public if their organisastion is powerful enough, and if they choose to do so.

Investigative journalism as a whole is very effective. It provides the best chance at getting as close to the truth as possible. Often times having an outside source like a journalist investigate something creates the closest version to the truth. They also have no benefit in changing the story often times, and can reach a large audience that regularly tunes in or reads their material.