Whistleblowers play a critical role in government accountability, and the Senate recognized that fact on Wednesday by passing a resolution designating July 30, 2014 as National Whistleblower Appreciation Day. The vote came by unanimous consent on the 236th anniversary of the first whistleblower law.

According to Sens. Chuck Grassley (R-Iowa) and Ron Wyden (D-Ore.), who sponsored Wednesday’s resolution, the original measure was enacted on July 30, 1778. It said: “Resolved that it is the duty of all persons in the service of the United States … to give the earliest information to Congress or any other proper authority of any misconduct, frauds or misdemeanors committed by any persons in the service of these states, which may come to their knowledge.”

By definition, whistleblowers are informants. Many are seen as heroes, but others are controversial. Below are a few examples of famous whistleblowers. You can be the judge of whether they deserve celebration.

“Deep Throat”

“Deep Throat” is the nickname that Washington Post reporters used for former FBI Associate Director W. Mark Felt, who provided information about President Nixon’s connection to the 1972 Watergate break-in. Nixon stepped down in 1974, earning the distinction of being the only U.S. president to resign from office.

Washington Post article described Felt this way in 2005, after Vanity Fair revealed that he was Woodward’s secret source:

“As the bureau’s second- and third-ranking official during a period when the FBI was battling for its independence against the administration of President Richard M. Nixon, Felt had the means and the motive to help uncover the web of internal spies, secret surveillance, dirty tricks and coverups that led to Nixon’s unprecedented resignation on Aug. 9, 1974, and to prison sentences for some of Nixon’s highest-ranking aides.”

Daniel Ellsberg 

Ellsberg was a military analyst who leaked the “Pentagon Papers,” first to The New York Times and then to The Washington Post. The documents revealed the U.S.’s growing political and military involvement in Vietnam leading up to the war there.

A 1996 New York Times article said the Pentagon Papers showed that the Johnson administration had “systematically lied, not only to the public but also to Congress.” Ellsberg was charged with conspiracy, espionage and theft of government property, but the charges were dismissed after a federal district judge declared a mistrial.

Edward Snowden

This former National Security Agency contractor leaked classified documents revealing that the federal government gathers information on private citizens as part of its massive electronic-surveillance program.

Snowden fled the United States, and Russia granted him temporary asylum. U.S. authorities charged him with espionage in June 2013.

Bradley Manning

This Army private, who changed his legal name to Chelsea Manning in April, turned over a huge trove of classified military and diplomatic records to the anti-secrecy group WikiLeaks.

An Army judge found Manning guilty of espionage in August 2013, sentencing him to 35 years in prison with a chance for parole in seven years. He was acquitted of aiding the enemy.

Linda Tripp

The former White House and Pentagon employee helped uncover President Clinton-Monica Lewinsky scandal in 1998, when she told the Office of Independent Counsel that Lewinsky had committed perjury when she filed an affidavit denying that she had a sexual relationship with the president.

Tripp was dismissed from her job with the Pentagon on the last day of the Clinton administration in 2001. She filed a lawsuit alleging that the Defense Department and Justice Department leaked information about her security file in violation of the Privacy Act of 1974, as retaliation for her actions in the Lewinsky matter. The federal government settled the case for nearly $600,000.