Final answer:
The Privacy Protection Act (PPA) is the U.S. law that offers protection for journalists against having to surrender their work or reveal their sources to law enforcement before publication.
Step-by-step explanation:
The U.S. law that protects journalists from turning over their work or sources to law enforcement before the information is shared with the public is the Privacy Protection Act (PPA). This act is a crucial tool that supports the concept of reporter's privilege, which is grounded in the First Amendment's protection of the press. Instances like Judith Miller's imprisonment for refusing to reveal her source and Edward Snowden's whistleblowing illustrate the complexities surrounding a journalist's right to protect their sources.
Moreover, the Supreme Court in Branzburg v. Hayes determined that a reporter's privilege is not absolute and in some cases journalists may be compelled to testify and reveal their sources. Despite this ruling, the PPA provides some protections, reflecting the delicate balancing act between the freedom of the press and the needs of law enforcement.