Not all data, mind you. The new rule wouldn’t reach the content of e-mail messages, but it would let them find out whom you’re e-mailing, when you’re e-mailing, and, er, “possibly” which websites you’re looking at and which Google searches you’re running. Sounds downright Bushian, which is why there are so many disgruntled lefties writing today about The One’s betrayal of his campaign promise to respect civil liberties more than you-know-who did. But then, that’s par for the course for Obama: As Eli Lake noted a few months ago, building on Bush’s war powers has been his M.O. since day one and will almost certainly continue to be so, partly because aggregating power is part of the inertia of institutions like the executive branch and partly because Obama knows he’ll suffer less politically from incremental encroachments like this than he would if a major attack happens on his watch. (Which, ironically, would likely generate public support for measures more draconian than looking at e-mail records.) In the end, he’s a politician worried about re-election. And like it or not, this probably helps him marginally towards that goal insofar as it marginally improves the speed with which the feds can act against terrorists — privacy concerns be damned:

Senior administration officials said the proposal was prompted by a desire to overcome concerns and resistance from Internet and other companies that the existing statute did not allow them to provide such data without a court-approved order. “The statute as written causes confusion and the potential for unnecessary litigation,” Justice Department spokesman Dean Boyd said. “This clarification will not allow the government to obtain or collect new categories of information, but it seeks to clarify what Congress intended when the statute was amended in 1993.”…

Administration officials noted that the act specifies in one clause that Internet and other companies have a duty to provide electronic communication transactional records to the FBI in response to a national security letter.

But the next clause specifies only four categories of basic subscriber data that the FBI may seek: name, address, length of service and toll billing records. There is no reference to electronic communication transactional records.

The officials said the transactional information at issue, which does not include Internet search queries, is the functional equivalent of telephone toll billing records, which the FBI can obtain without court authorization. Learning the e-mail addresses to which an Internet user sends messages, they said, is no different than obtaining a list of numbers called by a telephone user.

That’s certainly their best argument, and while they’re using classic slippery-slope reasoning to justify it — if X, why not Y? — it’s unclear to me why they’re not right about functional equivalents. How are e-mail addresses and timestamps on messages any more revealing than phone numbers and listings of when calls were made? (Browser histories are obviously a different ballgame.) They can be more revealing, of course: A call made to a pay phone won’t identify who’s on the other end of the line whereas an e-mail sent to an address that contains someone’s name tells you right away whom it’s meant for. But of course, the opposite scenario’s also possible: A call made to someone’s home phone or cell phone points to the identity of the recipient whereas a message sent to an e-mail address with no identifying info in the address reveals little at first glance about who owns it. Exit question: Should e-mail identifiers be given greater protection? And if so, is that simply in order to draw a line on the slope before the feds slip any further downward?