The National Security Agency has developed the capability to mine the thought patterns of millions of people simultaneously, collection that may involve thousands of Americans, according to the latest disclosure from former NSA contractor Edward Snowden.

An NSA Powerpoint slide refers to the classified program, code-named "MINDPRISM," as “The Ultimate in Upstream Collection.” A combination of the agency’s most powerful and sophisticated signals intelligence capacities and a new neuroscience program has given the agency the ability to capture communications---before they are even communicated. “NSA can no longer afford to operate at network speed,” the slide reads. “With MINDPRISM, we can stay one step of communication itself. If the target can think it, we can collect it.”

An NSA official familiar with the program describes it as the most forward-leaning of the NSA programs compromised by Snowden and complained that senior Al Qaeda leaders and Vladimir Putin had all begun changing the way and the amount that they think in response to the disclosures.

“We used to know what Putin was planning before he called anyone we were covering,” this official said. “Now we’re just getting a lot of hummed Russian advertising jingles---even in the run-up to the Crimea invasion. We’ve lost a huge asset here.”

At the request of the NSA, Lawfare is withholding both technical details of how MINDPRISM extracts thoughts and information in the Powerpoint slides about who is thinking about what. Broadly speaking, however, the slides describe a program that taps human thought through implants in dental work, beaming thought signals for satellite pickup to NSA’s network of supercomputers. A single implant can capture the thoughts of hundreds of people in the target’s vicinity, including Americans whose thoughts are not specifically targeted but are incidentally collected in large volume through the program.

The slides also reveal certain defensive measures about which NSA is concerned. “Some adversaries are frustrating MINDPRISM collection with improvised countersurveillance devices (ICDs) constructed from aluminum foil.” According to the slides, “crude foil ICDs wrapped around the target's cranium can both prevent collection against the target and impede ambient collection against vicinity targets.” The slides also suggest that certain orthodontic appliances---retainers, braces, and even headgear---might also undermine MINDPRISM’s operation.

Notwithstanding the technical problems, the official says NSA has learned a huge amount about important foreign adversaries from MINDPRISM. “Some of them are really distracted from their day jobs,” the official said. “It wasn’t just buxom Ukrainian nurses Qadhafi was thinking about, and Kim Jong Un really is obsessed with basketball. It’s literally all he thinks about. And that’s important to know.”

NSA spokeswoman Sandra Stanar-Johnson issued a statement saying that the agency would not comment on or confirm the authenticity of specific documents or the programs they purport to describe. But as a general matter, she said, "NSA does not scan the brains, even intermittently, of US persons without individualized approval of the FISC, extensive internal review, and full reporting to Congress. And any information on US persons obtained by implanting devices in the teeth of non-US persons overseas would be subject to rigorous minimization procedures."

It remains unclear exactly how individualized brainscan collection really is. MINDPRISM collection clearly involves bulk acquisition of the thoughts of foreigners overseas, and NSA also clearly overcollects, screening out US person thoughts, whose retention minimization procedures generally restrict, after the fact. But the slides also make passing reference to “bulk acquisition of meta-thought data,” which sources say refers to a separate program in which NSA collects records of people stewing about whether they should think about talking to people. “Collection of domestic metathought data is 87 percent comprehensive,” reads one slide. “Important gaps remain with respect to yoga practitioners, practitioners of Zen meditation techniques, and others who actively seek to clear their minds.”

The MINDPRISM program appears to implicate the work of more than one arm of the U.S. government; it is, for example, unclear exactly what agency or agencies might pore over the millions of ruminations harvested surreptitiously by the NSA. CIA officials referred Lawfare’s questions on the program to the NSA, given the NSA’s traditional competence in foreign surveillance activities. One CIA official, however, expressed admiration for the program, noting that by comparison, the CIA’s own notorious research into mind control, undertaken in the 60’s and codenamed MKULTRA, “now really looks like Mr. Rogers’ Neighborhood by comparison.”

Human rights and civil liberties groups blasted the MINDPRISM revelations. “Any debate over governmental mind-reading, on small or mass sale, ought to be held in public,” said Jameel Jaffer, the Deputy Legal Director of the American Civil Liberties Union, which is leading a legal challenge to the NSA’s surveillance programs. In court filings, his organization argues that the bulk collection of inner monologues is both unwise and unlawful; instead, Jaffer says, “thought scanning should only be conducted on a tailored, individualized basis, and with much more rigorous judicial and congressional oversight than we’ve seen so far in this program.”

The disclosure of a longstanding, highly intrusive brain-scanning apparatus comes at an especially awkward time for the Obama Administration, which in recent months had sought to reassure anxious allies about NSA eavesdropping. In particular, a recently unveiled White House policy directive had instructed the U.S. intelligence community, before engaging in electronic surveillance, to account for the dignity and privacy of all persons---foreign nationals as well as U.S. citizens. The directive, however, conspicuously omitted reference to mind-scraping in what now appears to be an intentional loophole.

The directive was widely thought to respond to diplomatic tensions with some European nations, the leaders of which had been monitored by the NSA pursuant to programs other than MINDPRISM. But now, MINDPRISM obviously stands to complicate the Obama Administration’s efforts at diplomatic rehabilitation. When asked if the surveillance would strain ties between the United States and Germany, German Chancellor Angel Merkel---whose telephone NSA had tapped---said, "you read my mind."

Reached poolside in Palm Springs, General Keith Alexander, the embattled agency’s former Director, sipped from his Mai Tai and told Lawfare that “this just isn’t my problem anymore. Anyone who wants them can have access to my thoughts, which are mostly about shuffleboard these days.”

Asked to comment on the newly disclosed NSA mind-reading, incoming FISA presiding judge Thomas Hogan issued only a brief statement: “Happy April Fools.”