WASHINGTON -- Can a company offer an email service that guarantees complete privacy and security, even from the prying eyes of the U.S. government?
That issue lies at the heart of a legal battle that has reached a federal appeals court between prosecutors and Lavabit, an email provider used by National Security Agency leaker Edward Snowden. The government's demand, say lawyers for Lavabit, "gutted the entire premise the company was built on."
Court documents do not explicitly identify Snowden as the object of the government's interest, but the timing and context leave no doubt it's him.
Beginning in June, shortly after federal espionage and theft charges were filed against Snowden, the government served a series of orders on Lavabit, requiring the company to provide access to the "from" and "to" address lines, times of origin and other information about Snowden's e-mails, though not the contents of the messages.
The company refused, arguing that complying with the government's demand would require giving up the very means that made its email service secure -- its encryption key, used by Lavabit's users to decode and read emails after they were encoded and sent through the Internet.
"That would have allowed the government to decrypt and intercept all encrypted communications that were sent between Lavabit and its customers," the company's lawyers said.
The government then served a grand jury subpoena on Lavabit and later a search warrant demanding access to the encryption key. After a court hearing, a federal judge ordered the company to either disclose the key or pay a $5,000 fine every day it resisted.
In August, the company owner, Ladar Levison, turned over the key and immediately shut down his email service. Barred at the time by federal law from disclosing the reason, he said simply that the company would cease operations rather than become "complicit in crimes against the American people."
Now Lavabit is asking the Fourth Circuit Court of Appeals in Virginia to rule that the disclosure orders were unlawful and allow the business -- which once had 400,000 customers -- to resume operations.
"For a company built on secure email services to surrender its private keys to an untrusted third party is a truly dramatic act," its lawyers argue in their appeal filed late Thursday, "akin to requiring a hotel to turn over a master key to all of its hotel rooms or install clear glass doors on those rooms."
What's more, the company says, a search warrant gave the government the ability to get access to the email data of all its customers, amounting to "an open-ended rummaging through the correspondence of hundreds of thousands of people, to seize a small amount of information about one person suspected of a crime."
The Justice Department, which has until Nov. 4 to respond, had no immediate comment on the appeal.
But an expert on the law governing searches said the government appears to have a strong position to defend.
"I think Lavabit faces a very uphill battle," said George Washington University law school Professor. Orin Kerr. "Lavabit is essentially claiming that its anti-government business model trumps the subpoena power. It is arguing that the subpoena is oppressive precisely because it would work.
"I don't know of any authority for the view that a private company can announce an ideology or business strategy and then say that a subpoena that interferes with that strategy is abusive or oppressive."
That's especially so, Kerr says, in light of the long-standing principle that federal courts have a right to every man's evidence.
Levison, the company's founder, told NBC's Michael Isikoff in August that he had raised more than $90,000 for a legal defense. One of the donors is former Texas Congressman Ron Paul.
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