A federal judge granted a preliminary injunction late Wednesday to block provisions of the 2012 National Defense Authorization Act that would allow the military to indefinitely detain anyone it accuses of knowingly or unknowingly supporting terrorism.

Signed by President Barack Obama on New Year's Eve, the 565-page NDAA contains a short paragraph, in statute 1021, letting the military detain anyone it suspects "substantially supported" al-Qaeda, the Taliban or "associated forces." The indefinite detention would supposedly last until "the end of hostilities."

In a 68-page ruling blocking this statute, U.S. District Judge Katherine Forrest agreed that the statute failed to "pass constitutional muster" because its broad language could be used to quash political dissent.

"There is a strong public interest in protecting rights guaranteed by the First Amendment," Forrest wrote. "There is also a strong public interest in ensuring that due process rights guaranteed by the Fifth Amendment are protected by ensuring that ordinary citizens are able to understand the scope of conduct that could subject them to indefinite military detention."

Weeks after Obama signed the law, Pulitzer Prize-winning journalist Chris Hedges filed a lawsuit against its so-called "Homeland Battlefield" provisions.

Several prominent activists, scholars and politicians subsequently joined the suit, including Pentagon Papers whistle-blower Daniel Ellsberg; Massachusetts Institute of Technology professor Noam Chomsky; Icelandic parliamentarian Birgitta Jonsdottir; Kai Wargalla, an organizer from Occupy London; and Alexa O'Brien, an organizer for the New York-based activist group U.S. Day of Rage. They call themselves the Freedom Seven.

In a signing statement, Obama contended that the language in Section 1021 "breaks no new ground" and merely restates the 2001 Authorization to Use Military Force (AUMF). Government lawyers whistled the same tune to swat away the lawsuit, but they failed to convince the judge that no changes had been made.

"Section 1021 tries to do too much with too little - it lacks the minimal requirements of definition and scienter that could easily have been added, or could be added, to allow it to pass constitutional muster," Forrest wrote.

Scienter refers to a person's knowledge that a law is being violated. "For the reasons set forth below, this court finds that § 1021 is not merely an 'affirmation' of the AUMF," Forrest wrote. "To so hold would be contrary to basic principles of legislative interpretation that require Congressional enactments to be given independent meaning. To find that § 1021 is merely an 'affirmation' of the AUMF would require this court to find that § 1021 is a mere redundancy - that is, that it has no independent meaning and adds absolutely nothing to the government's enforcement powers."

Brushing aside that argument, Judge Forrest took aim at government arguments that the NDAA did not affect Hedges and his co-plaintiffs personally. "Here, the uncontradicted testimony at the evidentiary hearing was that the plaintiffs have in fact lost certain First Amendment freedoms as a result of the enactment of § 1021," Forrest wrote.

At a hearing in March, three of the plaintiffs testified that the possibility of government repression under the NDAA made them reconsider how they approached their journalism and activism. Guardian journalist Naomi Wolf read testimony from Jonsditir, who prepared a statement saying that she would not visit the U.S. for fear of detention. Forrest alluded to this testimony in her decision.

"Hedges, Wargalla, and Jonsdottir have changed certain associational conduct, and O'Brien and Jonsdittir have avoided certain expressive conduct, because of their concerns about § 1021. Moreover, since plaintiffs continue to have their associational and expressive conduct chilled, there is both actual and continued threatened irreparable harm," she wrote.

"In addition, it is certainly the case that if plaintiffs were detained as a result of their conduct, they could be detained until the cessation of hostilities - i.e., an indeterminate period of time," Forrest continued. "Being subjected to the risk of such detention, particularly in light of the Government's inability to represent that plaintiffs' conduct does not fall with § 1021, must constitute a threat of irreparable harm. The question then is: Is that harm immediate? Since the Government will not say that the conduct does not fall outside of §1021, one cannot predict immediacy one way or the other. The penalty we know would be severe."

The judge added that she did not make the decision lightly.

"This court is acutely aware that preliminarily enjoining an act of Congress must be done with great caution," she wrote. "However, it is the responsibility of our judicial system to protect the public from acts of Congress which infringe upon constitutional rights. As set forth above, this court has found that plaintiffs have shown a likelihood of success on the merits regarding their constitutional claim and it therefore has a responsibility to insure that the public's constitutional rights are protected."

In a phone conference, the plaintiffs' attorneys Bruce Afran and Carl Mayer hailed what they called a "complete victory." "America is more free today than it was yesterday due to the courageous and righteous and very sound ruling by Judge Forrest," Mayer said. "I think this is a hugely significant development... I think it's also a testament to the courage of the plaintiffs here."

One of those plaintiffs, O'Brien, was also jubilant in a separate interview.

"I am extremely happy right now, and what I'm most happy about it is that this ruling has given me trust," O'Brien said, "Trust is the foundation of just and stable governments, and this ruling gives me hope that we can restore trust in the foundations of government."

While the U.S. Attorney's office declined comment on the ruling, Mayer urged the Obama administration to "drop it," and forego an appeal.

"They have to come to terms with the fact that it's wholly unconstitutional," Mayer said.