Senator Feinstein Admits the NSA Taps the Internet Backbone

We know from the Snowden documents (and other sources) that the NSA taps Internet backbone through secret-agreements with major U.S. telcos., but the U.S. government still hasn't admitted it.
In late August, the Obama administration declassified a ruling from the Foreign Intelligence Surveillance Court. Footnote 3 reads:

The term 'upstream collection' refers to NSA's interception of Internet communications as they transit [LONG REDACTED CLAUSE], [REDACTED], rather than to acquisitions directly from Internet service providers such as [LIST OF REDACTED THINGS, PRESUMABLY THE PRISM DOWNSTREAM COMPANIES].

Here's one analysis of the document.
On Thursday, Senator Diane Feinstein filled in some of the details:

Upstream collection…occurs when NSA obtains internet communications, such as e-mails, from certain US companies that operate the Internet background [sic, she means "backbone"], i.e., the companies that own and operate the domestic telecommunications lines over which internet traffic flows.

Note that we knew this in 2006:

One thing the NSA wanted was access to the growing fraction of global telecommunications that passed through junctions on U.S. territory. According to former senator Bob Graham (D-Fla.), who chaired the Intelligence Committee at the time, briefers told him in Cheney's office in October 2002 that Bush had authorized the agency to tap into those junctions. That decision, Graham said in an interview first reported in The Washington Post on Dec. 18, allowed the NSA to intercept "conversations that . . . went through a transit facility inside the United States."

And this in 2007:

[The Program] requires the NSA, as noted by Rep. Peter Hoekstra, "to steal light off of different cables" in order to acquire the "information that’s most important to us" Interview with Rep. Peter Hoekstra by Paul Gigot, Lack of Intelligence: Congress Dawdles on Terrorist Wiretapping, JOURNAL EDITORIAL REPORT, FOX NEWS CHANNEL (Aug. 6, 2007) at 2.

So we knew it already, but now we know it even more. So why won't President Obama admit it?