A federal appeals court on Wednesday rejected an appeal of a conviction and sentence of life in prison for Ross Ulbricht, founder of the online Silk Road marketplace that allowed users to buy illicit goods and services discreetly.

The 2nd Circuit Court of Appeals affirmed a lower court's ruling against Ulbricht, the accused Silk Road founder "Dread Pirate Roberts," but part of the decision could have an impact on litigation regarding Internet privacy outside the scope of Ulbricht's case. The appeals court ruled the "recording of IP address information and similar routing data, which reveal the existence of connections between communications devices without disclosing the content of the communications" is legal and not subject to Fourth Amendment protections because there is no reasonable expectation of privacy with that information.

Judge Gerard E. Lynch wrote the court's unanimous 3-0 decision disagreeing with Ulbricht's claims that much of the evidence against him should have been deemed invalid partially because it was "obtained in violation of his Fourth Amendment rights."

Acting upon orders issued from the Southern District of New York, the government deployed five pen registers and trap and trace devices to monitor IP addresses connected to Internet traffic running through Ulbricht's home router and devices connected to the router. As defined by the court, a pen register "records or decodes dialing, routing, addressing, or signaling information transmitted by an instrument or facility from which a wire or electronic communication is transmitted" but does not go into the content of the communications. A trap and trace device "captures the incoming electronic or other impulses which identify the originating number or other dialing, routing, addressing and signaling information reasonably likely to identify the source of a wire or electronic communication."

Ulbricht said the orders, obtained under the Pen/Trap Act, violated the Fourth Amendment because they were obtained without a warrant. The court wrote that a statute in the act does not necessitate a warrant for use of either device, instead requiring only "certification ... that the information likely to be obtained is relevant to an ongoing criminal investigation."

"The Supreme Court has long held that a 'person has no legitimate expectation of privacy in information he voluntarily turns over to third parties,' including phone numbers dialed in making a telephone call and captured by a pen register," Lynch wrote in the 2nd Circuit's opinion. Lynch equated IP addresses and such information with phone numbers and noted that the 2nd Circuit "remain[s] bound" by Supreme Court precedent.

"Whatever novel or more intrusive surveillance techniques might present future questions concerning the appropriate scope of the third-party disclosure doctrine, the orders in this case do not present such issues," Lynch wrote. "The recording of IP address information and similar routing data, which reveal the existence of connections between communications devices without disclosing the content of the communications, are precisely analogous to the capture of telephone numbers at issue in Smith. That is why the orders here fit comfortably within the language of a statute drafted with the earlier technology in mind."

Since the court did not look at the content of Ulbricht's communications under the orders from the lower court, the federal appeals court's opinion said it did not need a warrant to gather IP address routing information and Ulbricht did not have "a legitimate privacy interest." The court noted that Internet service providers —such as telephone companies — require the disclosure of identifying information "in order to make communication among electronic devices possible."

The decision is likely to be of interest to lawmakers and interest groups set to debate the reauthorization of certain NSA surveillance programs before the end of 2017. The 4th Circuit Court of Appeals issued a separate opinion this month ruling that Wikimedia, a nonprofit that owns Wikipedia, had standing to challenge an NSA surveillance program likely to face new scrutiny this winter when Congress decides to reauthorize certain surveillance programs.