The protection of sources, sometimes also referred to as the confidentiality of sources or in the U.S. as the reporter's privilege, is a right accorded to journalists under the laws of many countries, as well as under international law. It prohibits authorities, including the courts, from compelling a journalist to reveal the identity of an anonymous source for a story. The right is based on a recognition that without a strong guarantee of anonymity, many would be deterred from coming forward and sharing information of public interests with journalists. As a result, problems such as corruption or crime might go undetected and unchallenged, to the ultimate detriment of society as a whole. In spite of any such legal protections, the pervasive use of traceable electronic communications by journalists and their sources provides governments with a tool to determine the origin of information. In the United States, the federal government legally contends that no such protection exists for journalists.
A famous instance of the use of an anonymous source is the series of articles by Washington Post reporters Bob Woodward and Carl Bernstein which uncovered the Watergate Scandal, ultimately leading to the resignation of US President Richard Nixon. Woodward and Bernstein relied extensively on information provided by someone known to the world only under the nickname Deep Throat. Woodward and Bernstein were not forced to invoke the protection of sources, since the US authorities made no attempt to uncover the identity of "Deep Throat". In 2005 W. Mark Felt, who at the time had been Associate Director of the US Federal Bureau of Investigation, revealed that he was "Deep Throat".
An example of the legal operation of the right is the case of Bart Mos and Joost de Haas, of the Dutch daily De Telegraaf. In an article in January 2006, the two journalists alleged the existence of a leak in the Dutch secret services and quoted from what they claimed was an official dossier on Mink Kok, a notorious criminal. They further alleged that the dossier in question had fallen into the hands of Kok himself. A subsequent police investigation led to the prosecution of Paul H., an agent accused of selling the file in question. Upon motions by the prosecution and the defence, the investigative judge in the case ordered the disclosure of the source for the news story, on the grounds that it was necessary to safeguard national security and ensure a fair trial for H. The two journalists were subsequently detained for refusing to comply with the disclosure order, but were released on appeal after three days, on November 30. The Hague district court considered that the national security interest served by the order was minor and should not prevail over the protection of sources.