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Jeffrey Feldman has won a reprieve from a federal court order that had given him until Tuesday to decrypt his hard drives for the FBI -- or face contempt of court.

A federal judge in Wisconsin today granted an emergency motion filed by Feldman's attorney for additional time to establish that her client's Fifth Amendment right to self-incrimination would be violated.

U.S. District Judge Rudolph Randa lifted the threat of contempt of court and jail time, at least temporarily, and asked for additional briefs from Feldman's attorney and Justice Department prosecutors. A hearing is likely to take place this fall.

The Wisconsin case, in which an FBI agent accused Feldman of possessing underage porn, is the latest to test the limits of the Fifth Amendment in the digital age. The Fifth Amendment says that nobody may be "compelled in any criminal case to be a witness against himself," which has become known as the right to avoid self-incrimination.

Feldman's attorney, Robin Shellow, argued in an emergency motion filed yesterday that a previous magistrate judge had "no authority to issue an order" to require her client to decrypt his Western Digital My Book and Maxtor Black Armor hard drives. Of approximately 20 terabytes of storage, about 80 percent is encrypted, the government claims.

Shellow also argued that the decryption order was improper because the previous proceedings were held before a magistrate judge with only prosecutors -- not defense counsel -- permitted to attend. Judge Randa agreed, and requested both sides submit additional arguments in briefs due in July and August.

Prosecutors did not respond to a request for comment. Shellow told CNET this afternoon that:

I will move heaven and earth to make sure that the war on the infinitesimal amount of child pornography that recirculates on the Internet does not eradicate the Fifth Amendment the way the war on drugs has eviscerated the Fourth Amendment. This case is going to go many rounds. Regardless of who wins the next round, the other side will appeal, invariably landing in the lap of the Seventh Circuit Court of Appeals and quite possibly the U.S. Supreme Court. The grim reality facing our country today is one where we currently have a percentage of our population behind bars that surpasses even the heights of the gulags in Stalinist Russia. On too many days criminal lawyers lose all rounds. But for today: The Shellow Group: 1, Government: 0.

FBI agent Brett Banner said in an affidavit the bureau obtained a warrant to seize hard drives and other electronic gear from Feldman's house in January 2013. They found 20 terabytes of hard drives, but agents in the Milwaukee field office could not break the encryption despite spending "over 10 weeks working" on the task. Banner said agents did find evidence that suggested Feldman was using a peer-to-peer program called eMule to exchange files with titles suggestive of child pornography.

While the U.S. Supreme Court has not confronted the topic of the Fifth Amendment and encryption, a handful of lower courts have.

A federal judge in Colorado ruled last year that a woman accused of being involved in a mortgage scam would have to decrypt her laptop. A Vermont federal judge reached the same conclusion in 2009.

But in March 2010, a federal judge in Michigan ruled that Thomas Kirschner, facing charges of receiving child pornography, would not have to give up his password. That's "protecting his invocation of his Fifth Amendment privilege against compelled self-incrimination," the court ruled (PDF).

The question of encryption and the Fifth Amendment has been around at least since the 1990s, with law review articles sparring over which traditional legal analogy is most apt. Prosecutors tend to view passphrases as akin to someone possessing a key to a safe filled with incriminating documents. That person can, in general, be legally compelled to hand over the key. Other examples include the U.S. Supreme Court saying that defendants can be forced to provide fingerprints, blood samples, or voice recordings.

Civil libertarians, however, cite a different set of Supreme Court cases that conclude Americans can't be forced to give "compelled testimonial communications." Courts already have ruled that that such protection extends to the contents of a defendant's mind, the argument goes, so why shouldn't a passphrase be shielded as well?

In the current Wisconsin case, the now-vacated order from U.S. Magistrate Judge William Callahan ordered Feldman to meet with the FBI and either "enter the appropriate password or passwords...to decrypt those devices" or otherwise help them decrypt it by the end of the day today.

Update, 4:40 p.m. PT: Adds comment from Feldman's attorney.