The main purpose of investigative journalism is to expose the wrong doings that is conducted by individuals, corporate entity, or government officially. In order to conduct this type of journalism, journalists typically utilize some sort of inside informant (which is most commonly known as whistle blower)
One of the latest example of famous investigative journalism would be the document leaked by Edward Snowden, which later on uncovered the fact that the United States CIA directly steal private information from common citizens without any justifiable causes.
