Other forms: whistleblowers
A whistleblower is someone who reveals illegal activity that's been going on at their workplace. By making their allegations, most whistleblowers put their jobs in jeopardy.
Whistleblowers have exposed all kinds of wrongdoing at both private companies and government agencies, from fraud and illegal hiring practices to corruption and public health dangers. Many historians consider Benjamin Franklin to be the first U.S. whistleblower, for leaking letters between British officials, an action that was seen as a step toward revolution. The term wasn't applied to the act of revealing secret information until the 1970s, when activist Ralph Nader used it lieu of negative words like "snitch."