The government's vast secrecy bureaucracy does two things with great frequency. The first, of course, is keeping secrets. The second is devising elaborate reasons why you can't know what those secrets are.

It's hardly a secret that the government overclassifies basic information about what it does. What often gets overlooked is that the reasons it cites are often absurd. Sometimes they're craven cover-ups learned years after the fact. Sometimes they're ironic – or cynical – invocations that disclosure would aggravate the very problem it's supposed to solve. Sometimes they're bald contradictions of established policy or routine procedure.

Either way, the government has left a long, twisted trail of pretzel logic when it comes to all of the reasons you can't know what it's doing. Here are some of the lowlights.

Nuclear Experiments on People Would Have 'Adverse Effects on Public Opinion' —————————————————————————-

Government secrecy is perhaps at its most pronounced with nuclear weapons. And most people would probably agree that discretion is the better part of valor when it comes to the US's most dangerous arsenal. But that leeway probably doesn't extend to atomic experiments on human beings. Still, back in the 1940s, the Atomic Energy Commission decided you couldn't know about anything of the sort.

We now know that at the dawn of the nuclear age, the commission indeed used human guinea pigs to learn what the effects of atomic blasts and lingering radiation would be on the human physiology. In 1947, the commission wanted word that it was, among other things, feeding irradiated food to handicapped children kept very quiet. Its rationale was straightforward in its brazenness: We don't want to be sued by an outraged public.

"It is desired that no document be released which refers to experiments with humans and might have adverse effects on public opinion or result in legal suits," Army Col. O.G. Haywood Jr. wrote to fellow commission personnel on April 17, 1947. The memo's title itself is an artifact of the days when government personnel felt safe to engage in a baldfaced cover-up: "Subj: MEDICAL EXPERIMENTS ON HUMANS." (.pdf)

Haywood succeeded. Word of these atomic experiments – a practice that continued for another 15 years – came to light only after a savvy reporter named Eileen Welsome began exhuming long-forgotten documents at Kirtland Air Force Base in 1987. What she uncovered after a six-year inquiry would later compel President Clinton to form a major commission that ultimately led to official compensation for some of the family members of nuclear test subjects. Even Haywood couldn't keep everything a secret.

Fidel Castro (center, with beard) visits Berlin. Photo: Wikimedia

Knocking Off Castro Would 'Cause Public Confusion' ————————————————–

The 1961 Bay of Pigs fiasco was one of the worst foreign policy disasters of the 20th century. A plan hatched by CIA to overthrow the communist government of Fidel Castro led to the training of what President Kennedy was assured was a crack team of exiles – who were quickly rounded up and killed or captured almost as soon as they hit the Cuban beach.

Most accounts of the Bay of Pigs fiasco are incomplete or confusing. That's by design. Historians have long tried to get the CIA to disclose details surrounding the plot. The final volume of the CIA's official history has never seen daylight outside of Langley. When the disclosure advocates at George Washington University's National Security Archive tried to read it, they learned that the CIA thought your minds are too feeble to comprehend just what happened.

In 2005, the CIA explained that it was keeping the volume secret because it risked placing "inaccurate or incomplete information into the public domain." Scholars, reporters and the public might reach an "erroneous or distorted view of the Agency's role in the events described in a draft or otherwise lead to public confusion." This "inaccurate" "draft" is part of the CIA's official history of the Bay of Pigs.

The CIA's obstinacy might have more to do with its displeasure with the volume. It's criticized it as a "polemic of recriminations against CIA officers who later criticized the operation and against those U.S. officials who its author, [CIA historian Jack] Pfeiffer, contends were responsible for the failure of that operation." In other words, you can't read it because it makes the CIA look incompetent and petty.

CIA director George Tenet testifies before the 9/11 Commission. Photo: AP / Charles Dharapak

Budget Math Will 'Cause Damage to the National Security' ——————————————————–

George Tenet: one of the worst CIA directors ever or the worst CIA director ever? The case against Tenet usually starts and stops with failing to stop 9/11 and swearing Saddam Hussein had weapons of mass destruction. Sharp observers of Tenet noticed he'd be a problem back in 1999, when he told a federal court that he couldn't reveal how much the CIA's budget is – even though he had done exactly that for the previous two years. Why? If he did, your grandmother, neighbors, and all of their pets might perish.

In 1997, Tenet revealed to Congress publicly that the Clinton administration wished to spend $26.6 billion on intelligence activities. (Back then, the CIA director oversaw all 16 spy agencies; thanks to Tenet's screwups, that's no longer the case.) In 1998, Tenet revealed to Congress publicly that the Clinton administration wished to spend $26.7 billion on intelligence activities. In 1999, Tenet demurred. "I have determined that release of the Administration's intelligence budget request or total appropriation for fiscal year 1999 reasonably could be expected to cause damage to the national security, or otherwise tend to reveal intelligence methods," he said.

Steve Aftergood, the secrecy scholar at the Federation of American Scientists, promptly sued Tenet to learn what the figure was – and why he suddenly couldn't know how much cash the CIA wanted. Tenet's reasons reduced to what the great New York MC Jeru The Damaja once called the Wrath of the Math. That is, by comparing subsequent budget figures, someone could figure out the direction of the CIA's budget trends. And that would lead to chaos.

But wait, you say. Couldn't someone make precisely the same determination based on the 1997 and 1998 budget figures that Tenet himself released? Ah, Tenet responded in court: "the 1998 appropriation represented approximately a $0.1 billion increase – or less than a 0.4 percent change – over the 1997 appropriation" and so "release of the 1998 appropriation could not reasonably be expected to cause damage to the national security." Bigger fluctuations could provide no such guarantee.

Believe it or not, Tenet won this fight. But Aftergood won the war for common sense. In 2009, Dennis Blair, President Obama's first director of national intelligence, disclosed more of the intelligence budget than any of his predecessors combined. Miraculously, no one died.

A network operations center at Barksdale Air Force Base. Photo: USAF

It Would Violate Your Privacy for the NSA to Say if It Violated Your Privacy —————————————————————————-

The National Security Agency hoovers up a massive amount of voice, text, and other data from Americans communicating with foreigners, thanks in large part to a 2008 law that legalized President Bush's controversial warrantless surveillance program. No one knows how many Americans have been spied on. And on Monday, the NSA told two skeptical senators that it can't determine just how many – lest it violate citizens' privacy.

The inspectors general of the director of national intelligence (DNI) and the NSA, joined by "NSA leadership agreed that an IG review of the sort suggested would itself violate the privacy of U.S. persons," read a letter from the DNI's in-house watchdog to Senators Mark Udall and Ron Wyden. For good measure, the NSA inspector general pled that "obtaining such an estimate was beyond the capacity of his office and dedicating sufficient additional resources would likely impede the NSA's mission." That mission, of course, includes spying on you.

The NSA didn't release this argument at any old time. It released it the day before a House panel was set to vote on renewing the 2008 law expanding the NSA's surveillance authorities. That's why Wyden and Udall wanted the figure out there: so legislators would know just what they were voting on. "A federal agency can write a tart, dry non-response like this," thundered Jim Harper of the libertarian Cato Institute, "because Congress is utterly supine before the security bureaucracy."

Sure enough, on Tuesday that House panel gave the NSA's surveillance powers a big thumbs up – all without knowing just how vast those powers are.

This armed drone won't tell you anything about its mission, either. Photo: Flickr/An Honorable German

Obama Can Talk About Drone Strikes, Just Not the Agency That Performs Them ————————————————————————–

In 2012, just in time to run for reelection as a tough guy, President Obama began discussing an open secret that's defined his presidency: the expansive shadow wars, usually waged with armed drones, he has ordered against al-Qaida in Pakistan, Yemen and beyond. "In full accordance with the law – and in order to prevent terrorist attacks on the United States and to save American lives – the United States government conducts targeted strikes against specific al-Qaeda terrorists, sometimes using remotely piloted aircraft, often referred to publicly as drones," disclosed his chief counterterrorism adviser, John Brennan, in April.

Before Brennan's speech, administration officials couldn't even say the word "drone" without disclosing classified information. But Brennan's announcement didn't convince the CIA that it can follow his lead. While it's wrapped up in a lawsuit over the scope of its drone program, it told a federal judge it would neither confirm nor deny the existence of exactly what Brennan said existed.

For two years, the ACLU – where, full disclosure, my wife works – has sued the CIA to compel disclosure of information related to the drone attacks, like who is an appropriate target. The CIA, even after Brennan's speech, has responded by lawyering the issue to death. Such disclosure would "would reveal information that concerns intelligence activities, intelligence sources and methods, and U.S. foreign relations and foreign activities, the disclosure of which reasonably could be expected to cause damage to the national security of the United States," wrote lawyer Catherine Hancock.

Wait, hadn't Leon Panetta, the former CIA director, discussed the drone program himself at times? No matter, Hancock argued: "Director Panetta's statements certainly did not confirm the existence of any CIA records on the use of drones responsive to plaintiffs' [Freedom of Information Act] request." It's the legal equivalent of trolling: the ACLU should lose its case because government officials haven't publicly discussed precisely the secret records the ACLU wants.

This is an active legal case. As our sister blog Threat Level reported, even after Brennan confirmed the drone strikes, Hancock continued to argue that "even if there is speculation about a fact, unless an agency officially confirms that fact, the public does not know whether it is so." And hey, Brennan works for the White House, which isn't an agency. So forget about learning why the president can order flying death machines to kill American citizens.