As Eric Holder reflects on his six years as attorney general, one disturbing aspect of his legacy should give him significant pause. On Holder's watch, legal protections traditionally afforded to communications between reporters and sources have been torn down, potentially damaging for years to come the media's ability to uncover and report on government missteps. The attorney general should acknowledge the problems and address them before leaving office.

Holder has faced harsh criticism for pursuing two related strategies that undermined reporter-source communications. The first denied that any "reporter's privilege" exists - and just this year the Supreme Court let stand an appellate court ruling adopting Holder's position.

That ruling came in response to a prosecutor's demand that Pulitzer Prize-winning reporter James Risen disclose his source for a report on the CIA's effort to subvert Iran's nuclear program. Although a reporter's privilege has been recognized for decades in other contexts, a divided court of appeals accepted the Justice Department's argument that no evidentiary privilege allowed Risen to refuse to identify his source in a criminal prosecution. Under this ruling, the question of whether to require a reporter to reveal a source rests with the prosecutor alone.

The ruling is an unflinching rejection of a reporter's right to make a binding promise of confidentiality in exchange for information. It is a direct assault on the foundation of trust needed for effective investigative reporting and threatens to limit severely disclosures by government whistleblowers. That Holder's Justice Department fought for just this ruling caused some media lawyers to label this administration "worse than Nixon" for the free press.

The impact of this ruling is compounded by a second Holder strategy: relaxing regulations limiting prosecutors' surreptitious surveillance of reporters' communications.

For 40 years, there have been relatively few subpoenas for reporters' telephone records or e-mail, primarily due to strict Justice Department rules respecting the confidentiality of reporters' communications. Adopted in the 1970s after disclosures of the Nixon administration's misuse of government investigatory powers against "enemy" reporters, the rules limited when prosecutors could secretly obtain reporters' records. Department policy recognized that "freedom of the press can be no broader than the freedom of reporters to investigate" and expressly restricted federal prosecutors from using their investigatory powers in ways that "might impair the news gathering function." Prosecutors got the message.

In its zeal to hunt down whistleblowers, however, Holder's Justice Department expansively reinterpreted these rules. In one leak investigation, it secretly seized records for 20 phone lines used by dozens of Associated Press reporters over two months, even though the department knew the identities of the two reporters to whom the information was leaked and the days the leak occurred. In another investigation, the department told a court in a sealed affidavit that there was probable cause to believe a Fox News reporter violated the Espionage Act simply by asking a government source for confidential information, an accusation Holder now says he regrets. The unprecedented charge of criminality was made to obtain a warrant for the reporter's e-mail, even though the department had no intention of prosecuting him.

After the uproar last year when these seizures became public, President Obama instructed Holder to review the department's rules for obtaining information from reporters. When revised rules were released, however, they set off new alarms. The revisions made important improvements, covering modern forms of communication, closing the loophole that permitted the secret seizure of the AP's records and extending the rules to cover search warrant applications as was used to get the Fox e-mail. But the new Holder guidelines provided greater discretion for subpoenaing reporters and significantly watered down the message conveyed by the old rules - that prosecutors should rarely compel reporters to divulge information.

Gone is the explicit instruction to prosecutors not to "impair the news gathering function," replaced by a vague admonition to avoid issuing subpoenas if they "might unreasonably impair ordinary newsgathering activities." The rules provide no guidance for prosecutors of what actually constitutes "ordinary newsgathering" and seem certain to invite more subpoenas. New provisions can be read to eliminate the safeguards for reporters' communications at the request of the director of national intelligence. And they omit previous restrictions on the retention and use of seized information.

There is still time for Holder to make the corrections that are clearly needed. Without some legal protection for reporters' communications, essential sources of information inevitably will dry up. This truth was well understood by one of Holder's predecessors as attorney general - Robert Jackson - who in 1941 refused to release FBI reports to Congress because disclosure "would be of serious prejudice to the future usefulness of the" FBI. As he explained, some of the most valuable information obtained by the FBI "can only be obtained upon a pledge not to disclose its sources."

The same is true for news sources. The government may not like leaks about the Department of Veterans Affairs or CIA secret prisons, but our democracy depends on whistleblowers who will often talk to reporters only "upon a pledge not to disclose" their sources. If he wants to avoid being remembered forever as "worse than Nixon," the attorney general must act to correct these missteps.

The writer is a First Amendment lawyer and co-director of the Media Freedom and Information Access Clinic at Yale Law School. He has provided counsel to the Associated Press regarding the seizure of its phone records by the Justice Department.