Journalist that exposed corruption fraud and Injustice were referred to as

They are called Muckrackers

The best answer to the question: Journalists that exposed corruption, fraud and injustice were referred to as:___, would be: Muckrakers.

Explanation:

Especially during certain periods of particular political, social, or economical corruption, some journalists dedicated themselves to exposing the decay, and the bad practices that certain groups had adopted in detriment of what was just, what was fair, and what was right. These journalists, like Ida Tarbell, who dedicated herself to expose the corruption regarding the Standard Oil Trust Company, or Upton Sinclair, were known as muckrakers because their purpose was literally to dig in the muck, the dirt, the filth, of corrupted practices, and show them to the public. This is the reason for the despective name these journalists received.