In the five months since the world first learned of Edward Snowden, story after story based on documents disclosed by the young whistleblower have filled out a picture of the National Security Agency (NSA) as an organization with a limitless — and almost indiscriminate — hunger for information. Today, Glenn Greenwald, Ryan Gallagher, and Ryan Grim add a startling new dimension to that portrait by revealing that the agency has contemplated ways to use its troves of data to discredit and undermine individuals who the agency believes are "radicalizing others through incendiary speeches" but who lack any ties to actual criminality. The government is apparently seeking out "personal vulnerabilities" of these individuals, including their online sexual activity, hoping to expose them as hypocrites to their followers. While all of the targets are outside the United States, at least one of them is a U.S. person — meaning, either a citizen or a permanent resident.

As Greenwald notes, it's a story that's eerily reminiscent of past abuses of government surveillance authority. Greenwald's new report does not provide evidence of the NSA marshaling its vast databases to influence individuals or events within the United States. But you need not be a conspiracy theorist or a novelist with a knack for bending history to imagine how granting the NSA the power to "collect it all" might have seriously chilling and destructive repercussions here at home.

In fact, the NSA appears to be taking this effort right out of the shameful playbook of our not-so-distant history. Most infamously, as part of the COINTELPRO program, J. Edgar Hoover's Federal Bureau of Investigation (FBI) obsessively monitored the activities of Martin Luther King, Jr., picking and choosing from the results to produce a report chock full of insinuations about King's role in an evolving Communist conspiracy against the United States. Never mind that King unwaveringly espoused non-violence. It was King's rising public stature and broadly influential political ideas that led the government to see him as a threat.

The FBI viewed no space as off limits. The agency consistently bugged King's hotel rooms to monitor his planning of the 1963 March on Washington and to keep tabs on his strategic partnerships with other civil-rights leaders. But it also sought to compile a dossier of embarrassing information about King's private sex life that the government could (and did) employ to discredit King and obstruct his political efforts.

King was not alone on the government's long list of targets; he shared marquee billing with boxer Muhammed Ali, humorist Art Buchwald, author Norman Mailer , and even Senator Howard Baker. But the greater scandal was that — as the Church Committee revealed in 1976 — these big names appeared alongside more than one million other Americans, including half a million so-called "subversives."

That is why, as disturbing as it is to read about the FBI's sordid history of targeting domestic political "enemies," the potential of the NSA to revive those tactics today (as exposed by Greenwald's article) is alarming on a profoundly different scale. In the age of mass call-tracking and XKeyScore, hotel-room bugs seem almost quaint.

Indeed, Greenwald's new story is a warning shot to those of us who have thus far ignored the Snowden revelations on the basis of having "nothing to hide." As Greenwald makes clear, the subjects of the NSA's newly exposed effort to target individuals with influence on social media have tangential (if any) ties to real terrorists or violent extremists. And as the ACLU has explained , the entire premise of the NSA's focus on so-called "radicalizers" — the theory that a person's adoption of what the government views as "radical" ideas is a step to terrorism — has been debunked. Intelligence programs based on that discredited theory are not just wrong, they're ineffective. But they do very real damage to belief communities and political activists singled out for surveillance based on their views.

The efforts reported by Greenwald cut to the heart of the zone of expression and association that must remain free from intrusive, dragnet surveillance, both abroad and at home. In his very first public words, Snowden himself addressed the alarming consequences of the NSA's hunger for obtaining and storing an incomprehensibly vast record of our lives:

Even if you're not doing anything wrong, you're being watched and recorded...[T]hey can use the system to go back in time and scrutinize every decision you've ever made, every friend you've ever discussed something with, and attack you on that basis, to sort of derive suspicion from an innocent life and paint anyone in the context of a wrong-doer.

In the months since the first Snowden revelations, few have managed to evoke the existential threat presented by unhinged NSA surveillance with such plain, direct force. In an instant, Greenwald's new story has brought this surveillance nightmare— "collect it all" meets COINTELPRO — jarringly close to the here and now.