One respectable answer is that they don’t. Many an op-ed has been written to elaborate the point, but this won’t be one of them. Such answer is neither useful nor reassuring when we are speaking of our intelligence bureaucracy, which we can’t do without.

Here, we have to get things right.

The American surveillance state has grown tremendously in recent years, aided by digital technology, two ongoing wars, legitimate fears about terrorism, and a worrisome lack of oversight. Two events in the last two weeks underscored the growth of the surveillance state in some highly instructive ways — the WikiLeaks posting about 91,000 classified reports from Afghanistan, and the Washington Post exposé on “Top Secret America.” The Post series suggested that we suffer from a glut of classified information, and the WikiLeaks documents drove home the point.

To get an idea of how bloated our intelligence gathering has become, consider the plight of the Super User — one of those rare individuals so placed in the intelligence hierarchy that he or she can move about the usually compartmentalized matrix of classified information and make connections among the various parts. To simplify a very complicated role, Super Users are the ones who make sure the left hand know what the right hand is doing. But as the Post reports:

“I’m not going to live long enough to be briefed on everything” was how one Super User put it. The other recounted that for his initial briefing, he was escorted into a tiny, dark room, seated at a small table and told he couldn’t take notes. Program after program began flashing on a screen, he said, until he yelled “Stop!” in frustration. “I wasn’t remembering any of it,” he said.

It’s information overload. As blogger Matthew Yglesias notes, much (though certainly not all) of this secrecy seems to do little if any good. After combing the WikiLeaks documents, he writes,

I’m not sure much of what I’ve read thus far from the WikiLeaks document dump on Afghanistan has actually done a great deal to change my understanding of the war there. The Times is leading with the story that elements of Pakistani intelligence are supporting elements of the insurgency and the Guardian is emphasizing that coalition military operations have killed a lot of civilians, but I think most of us already knew both of those things. More broadly, the people most inclined to actually look at this material are going to be those of us who are already skeptical of the merits of long-term deep military engagement in Afghanistan. It is, however, a potent reminder that there’s far too much classification and secrecy in the United States government.

Much of the material is clearly neither sensitive nor embarrassing, and a good deal of it appears to be so abbreviated that it’s essentially uninformative, as war veteran and eyewitness Noah Schachtman has observed. Yet it was collected anyway and made classified. Perhaps this happened simply because information collection in the digital age is so ridiculously easy. More, though, does not always mean better, particularly not when what you really need is possibly a single piece of high-value information amid gigabytes of data. Whether routine mass information collection helps us fight more effective wars may well be doubted, and this is exactly the sort of question an informed citizen ought to ask of the government. Or at least our representatives, who are trusted with classified information, ought to be doing it for us.

There are worrying signs, however, that members of Congress either lack the willpower or the basic knowledge to do the job properly. Senator Jay Rockefeller recently expressed astonishment that retail sites like Ama​zon​.com collected information on every purchase you make. What’s even more astonishing is that a Senator could be unfamiliar with business-as-usual on the Internet. If he doesn’t know that private companies collect such massive amounts of data, what has the onetime Chairman of the Senate Intelligence Committee missed about our intelligence services?

Perhaps bureaucracies are fundamentally self-interested, just as economists say about the rest of us. William Niskanen, formerly of the Reagan Administration and now chairman emeritus of the Cato Institute, famously proposed a budget-maximizing economic model of bureaucracy. Later he ultimately agreed that budgetary discretion and managerial slack were important factors, too, and that other concerns may be at work as well. Still, control over large amounts of otherwise restricted information very obviously makes it easier for a bureaucracy to influence its budget, its discretionary spending, and its managerial slack.

None of which necessarily makes us any safer or better-informed about the threats we face. Our intelligence bureaucracy has grown with a speed that has caught many unawares. At the same time, the power of the Internet to disseminate leaked classified information gives us something of a peek behind the curtain. What we see suggests an enormous, haphazard collection of data, with little or no effective control or even organization. There’s only data, more data, and still more data, sped along by fear and incomprehension. I hope this picture is wrong, of course, but it’s hard to draw any other.