With its latest leak indictment last week, the Department of Justice under Donald Trump is now on pace to break the previous record for prosecutions of journalists’ sources, just two and a half years into its administration. A new report, released for the first time today, shows just how dangerous such cases can be to journalists.

In 2013, the Justice Department launched a brazen attack on press freedom, issuing sweeping subpoenas for the phone records of the Associated Press and several of its reporters and editors as part of a leak investigation. At the time, the subpoenas were widely seen as a massive intrusion into newsgathering operations. Last month, we learned that they told only part of the story.

A new report obtained by the Knight First Amendment Institute at Columbia University and the Freedom of the Press Foundation (where the authors work) under the Freedom of Information Act shows that the DOJ’s actions against the AP were broader than previously known, and that the DOJ considered subpoenaing the phone records of other news organizations, including The Washington Post, The New York Times, and ABC News. Moreover, they reveal how narrowly the DOJ interprets the Media Guidelines, the agency’s internal rules for obtaining reporters’ data.

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In May 2012, the AP published several articles about a successful CIA operation that thwarted a Yemen-based bomb plot. These articles contained classified information and their publication prompted a leak investigation. In February 2013, then Deputy Attorney General James Cole approved a request by DOJ attorneys to subpoena the telephone records of the AP as part of this investigation.

Although the purpose of the subpoenas was to identify the AP’s sources, the news organization was not given advance notice of them. Instead, more than a month later, it was informed that, at some unidentified earlier point in time, the DOJ had obtained records for 21 different phone lines associated with the organization, including AP general office numbers in Washington, New York, and Hartford, Connecticut, and the main number for AP reporters covering Congress—all over a two-month period.

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In its response, the AP argued that the subpoenas violated the Media Guidelines—which provide, among other things, that a subpoena for a reporter’s telephone records must be drawn as narrowly as possible—and interfered with the news organization’s First Amendment rights. The DOJ defended its position. Recently obtained documents, however, show for the first time that ethics lawyers in the DOJ’s Office of Professional Responsibility took the AP’s allegations seriously enough to investigate them.

The report, which was submitted to then–Attorney General Eric Holder in 2013, reveals that the leak probe was broader than previously understood. It reveals, for example, that, while the Justice Department obtained telephone toll records for 21 telephone numbers, the agency in fact issued “30 subpoenas to obtain telephone toll records for 30 unique telephone numbers.” The report reveals that those 30 subpoenas were intended to target seven reporters and editors, and covered a period of six weeks spanning April 1, 2012 to May 10, 2012.

The report also shows that, at least at one stage of their investigation, Justice Department attorneys considered subpoenaing the records of The Washington Post, The New York Times, and ABC News. What’s more, the report strongly suggests that the attorneys went so far as to obtain “telephone numbers and other contact information” for reporters and editors at those organizations who had worked on articles about the Yemen bomb plot. The report records, however, that the attorneys ultimately decided against issuing additional subpoenas.

The report is also important for what it tells us about the Justice Department’s Media Guidelines. Specifically, the report shows how weak the guidelines are, and how, in practice, the rules may offer little protection to journalists worried about being caught up in a criminal investigation. Although the guidelines have been revised since the AP subpoenas controversy, several of its standards remain intact. Among these is the requirement that proposed subpoenas be “narrowly drawn.”

While substantial portions of the Office of Professional Responsibility’s analysis are redacted, its finding that the AP subpoenas were “as narrowly drawn as possible” appears to have hinged on the perceived seriousness of the leak; the decision not to subpoena the telephone records for employees at the Post, the Times, and ABC News; the inability of investigators to determine to which AP reporter or editor the leaker had provided classified information; and “perhaps most importantly” the fact “the subpoenas requested the records for—and not the contents of—telephonic communications.”

The report ultimately concludes that DOJ attorneys involved in the decision to subpoena the AP’s records “did not engage in misconduct or exercise poor judgment.”

Disturbingly, the report does not come close to explaining why the subpoenas targeted the trunk lines of major AP offices—lines which could potentially reveal communications with confidential sources across all of the AP’s newsgathering activities. The report concludes that “although the [Justice] Department subpoenaed telephone records for several telephone numbers that subsequently were discovered not in fact to relate to an [AP] reporter or editors,” it was sufficient that “at the time when the subpoenas were sought, investigators had a factual basis for believing that those telephone numbers did relate to [AP] personnel.”

But merely requiring some evidence that a telephone number “relates to” a journalist is an extraordinarily low bar. In almost every case, the general phone numbers of a news organization will “relate to” any one of its reporters or editors.

Moreover, the notion that records for phone communications are not nearly as sensitive as the contents of those communications is dangerously misguided. As the Supreme Court recognized just last year, in Carpenter v. US, non-content phone data can provide an intimate window into a person’s life. For journalists, it can compromise the integrity of the newsgathering process by exposing the stories they are working on and the identity of countless sources.

Last year’s revelation that the Justice Department seized years of Times reporter Ali Watkins’s phone and email records makes clear that the DOJ continues to give short shrift to key limitations on its subpoena power. The subpoenas—which were used to obtain years of customer records and subscriber information for two of Watkins’s email accounts, and a phone number—swept extremely broadly, and many legal experts thought the Justice Department violated the Media Guidelines in issuing them. Yet the DOJ insisted that the seizure fully complied with the rules.

The Justice Department’s narrow interpretation of the Media Guidelines throws into sharp relief the weakness of some of the only legal protections journalists have. The Trump Administration’s recent threats to water down even these protections should sound alarm bells for anyone concerned about press freedom.

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Ramya Krishnan and Trevor Timm are the authors of this piece. Krishnan is a staff attorney at the Knight First Amendment Institute at Columbia University. Timm is the executive director of Freedom of the Press Foundation, a non-profit organization that supports and defends journalism dedicated to transparency and accountability. He is also a twice-weekly columnist for the Guardian, where he writes about privacy, national security, and the media.