Tor Exit Nodes: This One Weird Cop Trick Makes Getting a Warrant Easy
Apr. 12, 2016 (Mimesis Law) — At six in the morning on March 30, the Seattle Police Department executed a search warrant at the home of Jan Bultmann and David Robinson. The cops were purportedly there to look for child porn; they applied for the warrant on the basis of a tip from the National Center for Missing and Exploited Children, which had linked a child porn video uploaded by a 4chan user to the couple’s IP address.
(Interestingly, the SPD made the link between the IP address and the couple’s home with the help of MaxMind, an “IP intelligence” company best known for sending people to a small farm in northern Kansas whenever its geolocation approach fails.)
Robinson, who mistakenly believed he had no choice in the matter, turned over his computer passwords when asked. An hour later, the cops left. Their search was fruitless; they found nothing, seized nothing, and made no arrests.
Bultmann and Robinson were treated to the full assortment of delights that come with a police raid on your home at six in the morning. They were made to dress in full view of the officers, taken outside and shut in a van (though, of course, they weren’t necessarily in custody) and forced to wait as the police ransacked their possessions. The taxpayer generously agreed to foot the bill.
There’s really just one thing distinguishing this case from countless others: Bultmann and Robinson are privacy activists and cofounders of the Seattle Privacy Coalition, who have been very outspoken about running a Tor exit node out of their home. Oops. Needless to say, the warrant affidavit makes no mention of either fact.
Tor is a tool that encrypts a user’s traffic and anonymizes it by redirecting it through a worldwide network of computers, known as nodes or relays. Exit nodes like Bultmann and Robinson’s send traffic to the final destination intended by the user after it’s been bounced through several other relays.
Therefore, though Tor traffic appears to originate with the exit node once it’s been spit out of the system, it could actually have come from anywhere, and is, in fact, phenomenally unlikely to have been sent by people like Bultmann and Robinson. What’s more, because Tor traffic is encrypted, exit relay operators have no idea what’s passing through their node at any given time. They weren’t just innocent of any wrongdoing; they couldn’t have “helped the police with their inquiries” if they’d wanted to.
An SPD spokesman, Sean Whitcomb, told NPR the cops understand how Tor works and knew Bultmann and Robinson operated a Tor node before they executed the warrant on March 30. Separately, the police claimed they didn’t know about the node when they applied for the warrant March 28.
If both statements are true, the cops learned about the Tor node in the two-day interval between receiving the warrant and executing it, and then decided to go full steam ahead anyway. Alternatively, they’re lying. Either way, the judge who signed off on the warrant, Bill Bowman, told The Stranger the SPD didn’t see fit to let him know about any Tor node.
As with Stingrays, police departments are displaying a troubling willingness to lie in, and withhold information from, warrant affidavits. Until judges prove willing to hold the scorpions accountable, don’t expect the Fourth Amendment to offer you any protection.