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 gray 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.
AUDIE CORNISH, HOST:
When the FBI tried to force Apple to unlock that iPhone last month, it was a battle of titans - high-powered lawyers, PR strategies, the whole works. But what happens when law enforcement is frustrated by encryption that's run by private citizens? NPR's Martin Kaste has the story of one such person and the day last week when the police showed up at his door.
MARTIN KASTE, BYLINE: It was last Wednesday, a little after 6 in the morning when David Robinson found he had Seattle police coming into his bedroom.
DAVID ROBINSON: I was undressed, and so I started to reach to close the door when the cop steps through the door and says, no, I have to stand here while you're getting dressed.
KASTE: His wife had let them in because they had a warrant. They said a child pornography image had been traced to Robinson's home internet address. He says right away he knew what had happened.
ROBINSON: They were there because I run a Tor exit relay, and that means that traffic passes through my computers, and I don't know what it is.
KASTE: Tor - it stands for The Onion Router, and it's a system for surfing the internet anonymously. People use it to get around government censorship or hide from surveillance, but criminals use it, too. You may have heard about the narcotics black market called Silk Road which was busted by the feds back in 2013. Tor depends on Internet connections provided by thousands of volunteers, people like Robinson, who's also a privacy activist here in Seattle.
ROBINSON: What was upsetting about it was that they should have known.
KASTE: Robinson says he asked the police if they understood how a Tor relay worked.
ROBINSON: And one of the cops was a well-informed techie, and he said, yes, like, we understand what it is; we understand. I said, well, then you understand that I don't have any control or knowledge of things that pass over my network, and there's no reason for you to be coming in here and accusing me of having child pornography.
KASTE: Other privacy activists went online to complain about the surge, saying it was like raiding the post office because it had delivered a package containing contraband. The spokesman for Seattle Police, Sean Whitcomb, says his department gets that, but he takes the analogy a little further.
SEAN WHITCOMB: When that post office is also someone's personal residence, well, then in that case, yes, we do have an obligation to search for evidence of a crime. And in this case, we're not just talking about any crime. We're talking about child pornography, which is just an absolutely vile offense.
KASTE: Rightly or wrongly, a Tor volunteer risks being associated with crimes like that, especially if the Tor relay comes out of his home address. And when the police show up, that person is going to feel pretty alone, legally speaking.
JEFFREY FISHER: An individual is highly unlikely to have access to an attorney at his or her fingertips.
KASTE: Stanford Law professor Jeffrey Fisher worked on an important case involving police access to cell phones. He says volunteers like this may find themselves in a tough spot because there's still a lot of gray area when it comes to shielding technology from the police.
FISHER: Testing the legal boundaries of the police authority in this context could be extensive, difficult, cumbersome and perhaps treacherous.
KASTE: The people who run the global Tor Project say raids like this happen only occasionally, and they say even with a warrant, the police can't uncloak the encrypted communications that run through a volunteer's machine.
But that doesn't mean the police can't exert some pressure. There was a hint of that last summer in Lebanon, N.H., when a branch of the public library started hosting a Tor connection. Chuck McAndrew is the information technology librarian there.
CHUCK MCANDREW: The police department never actually told us to shut this down or anything like that. They did have some strong feelings against the use of the Tor network, and they had some concerns about the fact that the city library would be contributing towards this.
KASTE: But Tor supporters rallied to the cause, and the library kept hosting the connection. In Seattle, David Robinson says last week's police search hasn't changed his mind about Tor, either.
ROBINSON: 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. So I mean, I have every right to do this, and I wasn't doing anything wrong or unethical.
KASTE: To him, it's a matter of principle that he should be able to run a Tor relay out of his home without raising suspicions. Though, he admits that in practice, that's something he may have to reassess. Martin Kaste, NPR News, Seattle. Transcript provided by NPR, Copyright NPR.