Final answer:
The U.S. Supreme Court ruled in the 1972 Branzburg vs. Hayes case that the First Amendment does not protect reporters from revealing their sources under subpoena. States have enacted shield laws offering varying levels of protection for journalistic sources. Reporter's privilege has both supported press freedom and faced limitations, particularly in matters of national security or criminal proceedings.
Step-by-step explanation:
In the landmark case of Branzburg vs. Hayes in 1972, the U.S. Supreme Court ruled that the First Amendment does not shield journalists from subpoenas requiring them to reveal confidential sources. This 5-4 decision indicated that journalists could face contempt of court if they refuse to disclose this information. Despite the ruling, many states have enacted what is known as reporter's privilege, which offers various levels of protection for news sources.
The concept of reporter's privilege is complex and intersects with other First Amendment rights. There are situations where the line between the public's right to know and national security is tested, such as the Pentagon Papers case. While the Court generally supports the freedom of the press, there are limits, and cases like Branzburg vs. Hayes show that the confidentiality of sources is not absolute.
Nevertheless, these protections vary by state, and federal shield laws that would create a uniform level of protection for journalists' sources have been proposed but not enacted. As seen in subsequent cases, the Supreme Court has addressed challenges to press freedom, reinforcing the idea that reporters may sometimes need to reveal their sources, especially in situations involving national security or criminal investigations.