A federal judge in Washington has prevented the public release of information about a 2011 assassination plot targeting organizers of the Occupy Wall Street movement in Houston.

US District Judge Rosemary Collyer said Monday that the FBI was correct in refusing to release documents about the alleged conspiracy after reviewing the material herself.

The judge’s findings, in the court’s eyes, validate the federal agency’s claims that it was protecting informants within “organized violent groups”–a claim that the plaintiff in the case still contests.

The lawsuit was launched after Ryan Shapiro–a Cambridge, Mass.-based historian who studies how dissident groups in the US are policed–sued the FBI after a Freedom of Information Act request he filed on the matter returned 12 pages of redacted information.

News of the plans first surfaced in late 2012 after a separate FOIA request asking the FBI to reveal its records on the Occupy movement was lodged by the Partnership for Civil Justice Fund. One document among many others that responded to the filing detailed an individual who had “planned to engage in sniper attacks against protestors in Houston, Texas if deemed necessary.”

Judge Collyer had ruled last year that the FBI did not properly justify its withholding of information about the sharpshooter plot from Shapiro under the “law enforcement purposes” exemption to FOIA.

In response, FBI Information Dissemination Section Chief David Hardy argued that the material would reveal an FBI source.

“In this particular case, the specific nature for the compilation of these records relates to the investigation of threats made against those participating in the protests or reports received from a Confidential Human Source (‘CHS’) of other potential attacks against certain targets or entities,” he said last year in a declaration.

Upon review of the information, Collyer agreed.

But Shapiro still doesn’t believe that all the material withheld pertains to an investigation of “potential violence against protest participants.”

“I’m of course disappointed in, and disagree with, the judge’s ruling,” he said on Friday to Courthouse News. “I’m now conferring with my attorney to determine next steps.”

Shapiro said that the FBI has claimed, in other FOIA litigation to which he is a party, that it never launched an investigation into the Occupy movement.

“Yet, in the course of my FOIA lawsuit against the FBI for records about the sniper plot against Occupy Houston, the FBI contradicted its own position,” he said.

Documents about FBI spying on Occupy Chicago, he said, proves that members of the public will soon get the bureau “to concede it actually possesses a large volume of documents” in disclosures that will reveal Washington was involved in a “nationwide investigation of political protesters as supposed terroristic threats to national security.”

Federal law enforcement agents and their supporters are, however, extremely unlikely to cop to spying on activists engaging in Constitutionally protected activities. The material about Occupy Chicago–published in a Jan. 21 investigation conducted by In These Times’ Joel Handley and independent Chicago-based journalist Yana Kunichoff—reveals how the FBI relied on highly-teased and lawyered-up language to give cover to officials keeping a watchful eye on anti-capitalist protesters, and how the bureau ties free speech to violence.

A targeted individual named in the documents, “was participating in activities which are protected by the First Amendment,” FBI officials noted. “[However,] it is possible the protected activity could invite a violent or otherwise incendiary reaction towards the subject individual or others in retaliation or to stop the protected activity from occurring in the first instance.”

“Accordingly, information concerning protected activity is included in this alert for a limited purpose,” an FBI investigator claimed.