One thing that makes reporting on the NSA so difficult is that you have to deconstruct their statements like Derrida to figure out what they're actually saying. (This is why all responsible people read Marcy Wheeler.)
Luckily, here's an NSA issue anyone can sink their teeth into. It demonstrates the squirmy NSA legal technique, and how by its own logic the agency ought to be broken up or closed altogether.
The background is that the NSA is being sued around the block by all manner of people over the Snowden revelations. Pertaining to a suit brought by the Electronic Frontier Foundation, a previous court order had instructed the NSA to preserve data that it had collected under Section 702 of the Amendments Act to the Foreign Intelligence Surveillance Act.
That order has since been reversed, because the NSA has claimed (in addition to the usual business about how stopping this program will grievously harm American citizens) that it physically cannot store all the information it collects under Section 702. As Andrea Peterson at The Washington Post reported, the NSA's deputy director, Richard Ledgett, wrote a rather astonishing court filing, in which he said that "a requirement to preserve all data acquired under Section 702 presents significant operational problems, only one of which is that the NSA may have to shut down all systems and databases that contain Section 702 information." (Emphasis added.) Ironically, Ledgett claims that previous privacy restrictions that the Foreign Intelligence Surveillance Court placed on the program necessitate deleting the data the EFF wants preserved. You can practically see Ledgett sticking his finger in the eye of the EFF's legal director.
In any case, as Peterson notes, this puts the EFF in a strange position, since it is now arguing to preserve evidence for legal purposes it would ultimately want destroyed as a policy.
But aside from the legal arcana, this is an excellent example of the Kafkaesque logic that predominates when it it comes to our intelligence agencies. The NSA is almost saying, "We've got your privacy protections in here, honest, but unfortunately it just so happens that these protections mean we have to destroy all this evidence related to your lawsuit." Whatever the situation, it just so happens that the intelligence apparatus is regretfully excused from accountability. Marcy Wheeler is constantly uncovering various iterations of this stuff.
I'm skeptical that the data preservation the EFF is asking for is impossible. But the really troubling possibility is that the NSA is actually right. It's anybody's guess precisely how much data the NSA is shifting around, but it's reportedly in the exabytes overall. So yes, it might be impossible for the agency to store more than a few weeks or so of the data it's collecting.
The NSA's legal squirming is bad enough. But an agency writing itself a blank check to allegedly destroy evidence based on the sheer size and complexity of the possibly illegal program in question is another thing entirely. There shouldn't be an "unless your dragnet surveillance program is really big" exception to the Fourth Amendment.