Attorney General Eric Holder Jr. said he could not comment on the details of the phone records seizure, which he said was an open investigation — although he was happy to comment on the open investigation into the tax audits of conservative groups, which he said might have been criminal and were “certainly outrageous and unacceptable.”

Both Mr. Holder and Mr. Cole declared their commitment — and that of President Obama — to press freedoms. Mr. Cole said the administration does not “take lightly” such secretive trolling through media records.

We are not convinced. For more than 30 years, the news media and the government have used a well-honed system to balance the government’s need to pursue criminals or national security breaches with the media’s constitutional right to inform the public. This action against The A.P., as the Reporters Committee for Freedom of the Press outlined in a letter to Mr. Holder, “calls into question the very integrity” of the administration’s policy toward the press.

The records covered 20 phone lines, including main office phones in New York City, Washington, Hartford, and the Congressional press gallery. The guidelines for such subpoenas, first enacted in 1972, require that requests for media information be narrow. The reporters’ committee said this action is so broad that it allowed prosecutors to “plunder two months of news-gathering materials to seek information that might interest them.”

Mr. Holder said the leak under scrutiny, believed to be about the foiling of a terrorist plot in Yemen a year ago, “put the American people at risk,” although he did not say how, and the records sweep went far beyond any one news article. Gary Pruitt, the president of The A.P., said two months’ worth of records could provide a “road map” to its whole news-gathering operation.

Under the guidelines, the administration should have sought information from other sources. Mr. Cole said it did. But the administration made the troubling and discrediting decision not to inform The A.P. in advance. The guidelines require investigators to provide notice unless it would “pose a substantial threat to the integrity of the investigation.” That is intended to prevent destruction of evidence, an impossibility in this case.

The Obama administration has indicted six current and former officials under the Espionage Act, which had previously been used only three times since it was enacted in 1917. One, a former C.I.A. officer, pleaded guilty under another law for revealing the name of an agent who participated in the torture of a terrorist suspect. Meanwhile, President Obama decided not to investigate, much less prosecute, anyone who actually did the torturing.

The Justice Department is pursuing at least two major press investigations, including one believed to be focused on David Sanger’s reporting in a book and in The Times on an American-Israeli effort to sabotage Iranian nuclear works. These tactics will not scare us off, or The A.P., but they could reveal sources on other stories and frighten confidential contacts vital to coverage of government.