When the FBI tried to force Apple to unlock an iPhone last month, it was a battle of titans. There were high-powered lawyers and dueling public relations strategies. But when police encounter a privacy technology run by volunteers, things can be a little different.
For example, when Seattle police showed up at David Robinson’s home shortly after 6 a.m. last Wednesday, he figured he had little choice but to let them in and hand over all his computer passwords.
“They were there because I run a Tor exit relay,” he says. Tor (which stands for The Onion Router) is a system that allows people to surf the Internet anonymously. It’s sometimes referred to as the “dark Web,” and it relies on Internet connections provided by volunteers like Robinson.
“Traffic passes through my computers and I don’t know what it is,” he says. While Tor is useful for dissidents to evade government surveillance and censorship, it can also be used for less noble purposes. “It’s much like the post office or the telephone company. Anybody can use it. Bad guys can also use it.”
In this case, police said a child pornography image had been traced to Robinson’s home Internet address, and that was enough for them to get a warrant. But Robinson, who’s also a prominent privacy activist in Seattle, doesn’t think that justifies the early morning search.
“What was upsetting about it was that they should have known,” he says. Tor traffic is encrypted. Volunteers can’t see its contents, and it doesn’t leave a trace after it passes through an exit relay. He says the police seemed to imply that he shared responsibility for what came through his connection. At one point, a detective offered to show him the image, but Robinson refused.
“I said, ‘There’s no reason for you to be coming in here and accusing me of having child pornography,’ ” Robinson says.
Seattle police spokesman Sean Whitcomb says the department understands how Tor relays work, and they knew Robinson was a Tor host.
“Knowing that, moving in, it doesn’t automatically preclude the idea that the people running Tor are not also involved in child porn,” Whitcomb says. “It does offer a plausible alibi, but it’s still something that we need to check out.”
Whitcomb also says Seattle police were “artful” in the way they did the search. Instead of impounding all of Robinson’s computers, which the warrant would have allowed, they offered to search them on the premises as long as he consented to turning over his passwords. He did, and they let him keep his machines after they scanned them.
Tor itself is completely legal, and Seattle police say they have no objection to people hosting relays. But more broadly speaking, Tor can be frustrating for law enforcement agencies, especially those pursuing child pornography, Internet fraud and black markets.
“Tor certainly has the ability, if used by somebody who truly understands what it’s capable of, of thwarting police investigations,” says Jeff Fischbach, a forensic technologist with extensive experience working on criminal cases involving technology and encryption.
“At the same time, because so many people are using tools like that and don’t really understand them, in some ways I think the argument could be made that they’re aiding police,” Fischbach says. He’s referring to recent cases in which criminals’ excessive trust in Tor and similar technologies led them to fall into law enforcement stings.
An added wrinkle in Robinson’s case is the fact that he hosts the Tor exit relay from his home.
Stanford law professor Jeffrey Fisher worked on an important case involving police access to cellphones. He says Tor volunteers may find themselves in a tough spot, because there’s still a lot of grey area when it comes to shielding technology from the police.
“Testing the legal boundaries of the police authority in this context could be expensive, difficult, cumbersome and perhaps treacherous,” Fisher says.
Robinson admits it might be safer, legally, to host the Tor relay on rented space from a commercial Internet service to avoid mingling his personal traffic with Tor, but he says he shouldn’t have to.
“Why should I be spending extra money?” he asks. “There need to be more Tor exit nodes, more Tor nodes generally, and you don’t need to be discouraging people from doing it by intimidating them with bogus criminal complaints,” he says.
Given his early morning wake-up call last week and the fact that he may now have to get rid of his computers because he can’t be sure what the police did to them while he was being questioned outside his apartment, Robinson says he may have to reassess whether it’s practical for him to stand on that principle.