Our view: Compelling evidence of the need for a federal shield law for journalists can be found in a Washington, D.C., jail. While such a law may not have protected The New York Times' Judith Miller, who Wednesday chose jail rather than betray an anonymous source, it would greatly help shore up the eroding ideal of a free press in this country.

Whether you like us or not, journalists provide the public with an invaluable service. It's why the Founding Fathers firmly ensconced the freedom of the press in the First Amendment to the U.S. Constitution: to protect the common good by serving as an independent check on the government. Every state but one has adopted shield laws that grant privileges for reporters similar to those enjoyed by clergy, lawyers and doctors —— in other words, enabling journalists to keep secrets, so long as they don't infringe upon other constitutionally protected rights. But no such federal protection exists, and it's no coincidence that the recent rash of reporter prosecutions have come in federal courts.

Though anonymous sources must be used sparingly, in some cases they are vitally necessary. Without Woodward and Bernstein's promise to Mark Felt, aka "Deep Throat," we might never have learned of the Watergate conspiracy that ultimately forced President Richard Nixon to resign.

The case behind Miller's jail time seems more obscure. A federal judge held Miller and Time magazine's Matthew Cooper in civil contempt of court in November for refusing to reveal the people they spoke to in reporting on a Bush administration leak disclosed by conservative commentator Robert Novak. Novak revealed in his column that the wife of Joseph Wilson IV was a CIA agent after Wilson wrote an Op-Ed piece in July 2003 refuting the Bush administration's claim that Saddam Hussein had attempted to buy uranium from the African state of Niger. Federal prosecutors want to know who leaked Wilson's wife's name, a serious crime committed in the name of partisan politics.

Cooper's bosses even offered up his notes last week in an attempt to keep him out of jail. But Cooper was spared jail time only when the source released him from his pledge just moments before sentencing. Miller chose the high road, and all reporters and the public interest are in her debt. Ironically, Miller, the only person to be punished in this investigation thus far, never even wrote a story about the affair. What started out as a probe of government wrongdoing has devolved into intimidating reporters.

After the Supreme Court refused last month to review the appeal of Miller and Cooper, the onus is on Congress to recognize that our open society depends on the freedom of the press —— including the important ability to protect the identity of sources. A federal shield law may not have helped Miller and Cooper —— the anonymity of U.S. spies seems more important than the anonymity of news sources —— but we don't know that for sure. After all, the Watergate unraveling of the Nixon administration started with a botched break-in.