The legal commentators are starting to weigh in.
From Lynn Oberlander's "The Law Behind the A.P. Phone-Record Scandal," The New Yorker:
The cowardly move by the Justice Department to subpoena two months of the A.P.’s phone records, both of its office lines and of the home phones of individual reporters, is potentially a breach of the Justice Department’s own guidelines. Even more important, it prevented the A.P. from seeking a judicial review of the action. Some months ago, apparently, the government sent a subpoena (or subpoenas) for the records to the phone companies that serve those offices and individuals, and the
companies provided the records without any notice to the A.P. If subpoenas had been served directly on the A.P. or its individual reporters, they would have had an opportunity to go to court to file a motion to quash the subpoenas. What would have happened in court is anybody’s guess—there is no federal shield law that would protect reporters from having to testify before a criminal grand
jury—but the Justice Department avoided the issue altogether by not notifying the A.P. that it even wanted this information. Even beyond the outrageous and overreaching action against the journalists, this is a blatant attempt to avoid the oversight function of the courts.
From Orin Kerr's "Did the Leak of the CIA Operation in Yemen Justify “Very Aggressive Action” to Investigate Its Source?", Volokh Conspiracy:
The AP story tells us three important things: 1) The CIA knew about the details of the plot during its planning stages; 2) The CIA not only interrupted the plot but actually took the bomb into its possession and then passed it off to the FBI; and 3) the CIA’s work was occurring as recently as a few days before the AP story was published on 5/7/2012.
Based on those three facts, it seems pretty likely that the CIA had people “on the inside” of Al Qaeda’s Yemen affiliate who took possession of the bomb. As covert agents, they would have covered up their removal of the bomb by making it seem like something else had happened. That matters, I think, because it means that the Al Qaeda affiliates in Yemen have a ready way to find the CIA plant(s). Just trace back what happened to the bomb, and specifically find the folks who claim to have seen it last and who came up with some story about what happened to it around the beginning of May. Chances are, that would bring you to the guys working for the CIA. And that discovery probably means no more CIA plants working on the inside the next time, which may take away the person(s) who otherwise could disrupt future plots or tip off U.S. authorities to a future attack.
From Glenn Greenwald's "Justice Department's pursuit of AP's phone records is both extreme and dangerous," The Guardian:
The legality of the DOJ's actions is impossible to assess because it is not even known what legal authority it claims nor the legal process it invoked to obtain these records. Particularly in the post-9/11 era, the DOJ's power to obtain phone records is, as I've detailed many times, dangerously broad. It often has the power to obtain those records without the person's knowledge (as happened here) and for a wildly broad scope of time (as also happened here). There are numerous instruments that have been vested in the DOJ to obtain phone records, many of which do not require court approval, including administrative subpoenas and "national security letters" (issued without judicial review); indeed, the Obama DOJ has previously claimed it has the power to obtain journalists' phone records without subpoeanas using NSLs, and in its relentless pursuit to learn the identity of the source for one of New York Times' James Risen's stories, the Obama DOJ has actually claimed that journalists have no shield protections whatsoever in the national security context. It's also quite possible that they obtained the records through a Grand Jury subpoena, as part of yet another criminal investigation to uncover and punish leakers.
None of those processes for obtaining these invasive records requires a demonstration of probable cause or anything close to it. Instead, the DOJ must simply assert that the records "relate to" a pending investigation: a standard so broad that virtually every DOJ desire will fulfill it. Even if a court were involved in the acquisition of these records - and that's unlikely here - it typically does little more than act as rubber-stamping functionary, just as it does when secretly approving the DOJ's requests for FISA warrants. This is what is reaped from continuously vesting the US government with greater and greater surveillance powers in the name of Terrorism and other fears.