A shield law is a law which protects people from certain lines of legal inquiry. Shield laws are most commonly used to protect journalistic integrity, and to offer certain protections to people involved in sexual assault cases. Not all nations have shield laws, and the nature of such laws varies widely, with constant reforms to such laws being proposed by lawmakers.
In the context of journalism, a shield law protects journalistic sources. The idea is that people might be afraid to approach journalists with confidential information if they knew that journalists could be forced to reveal their sources, and that this would compromise the integrity of the news. Shield laws permit journalists to assure their sources that they will remain confidential, allowing journalists to get better stories.
In a classic example of the use of shield laws to protect journalists and their sources, Washington Post journalists Bob Woodward and Carl Bernstein refused to reveal the identity of “Deep Throat,” the source they used for their groundbreaking expose of the Watergate Scandal. Despite pressure to reveal their source, they declined to do so, until Deep Throat eventually outed himself in 2005.
Under a shield law, a journalist can decline to answer questions which could compromise his or her sources. This could be viewed as a protection similar to that offered to whistleblowers in some countries, with the goal of getting information into the public eye while protecting the source of that information from repercussions. Journalistic sources regularly risk losing their jobs or facing legal penalties to provide information, and they rely on shield laws for protection.
Some people argue that a story has more weight when the source is revealed, and journalists certainly prefer to use sources they can identify and quote, as it increases the integrity of the story. However, there are situations in which an anonymous source might be necessary, and such sources can be critical and invaluable, especially in the case of major breaking stories. By having a shield law for protection, journalists can access such sources with confidence.
In sexual assault cases, shield laws are used to sequester prejudicial evidence. For example, if a rape victim was not a virgin, this information could be viewed as prejudicial, so the defense would not be allowed to bring this topic up. Shield laws are also used to conceal the identity of victims of sexual assault, and to protect them from having to engage in damaging testimony. The defense, for example, cannot question the witness about his or her sexual history in nations with a rape shield law.