AUDIE CORNISH, HOST:
Time now for All Tech Considered.
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CORNISH: And today, surveillance and the law. If you're like me, you probably take your cell phone with you everywhere you go. That means that everywhere you go, you can be tracked and located through that cell phone. It's a feature of cell phones that's not often mentioned, but that is being used by law enforcement to catch criminals. And one particular practice raises legal, moral and practical questions for all of us. Manoush Zomorodi has been looking into the use of cell phone tracking devices for her podcast, WNYC's "Note To Self." Welcome back to the program, Manoush.
MANOUSH ZOMORODI, BYLINE: Hi, Audie. Great to be here.
CORNISH: So tell us more about these police tools. One of the most common is called a Stingray, right?
ZOMORODI: Yes. So a Stingray is a device that basically acts like a fake cell phone tower. It sends out a signal that talks to all the phones in the area, even if they're not being used. And the technical term is an International Mobile Subscriber Identity Catcher. And so it can be used to listen in on a cell phone, but most importantly, Stingrays can track a cell phone and its owner right down to the room or even the pocket that it's in.
CORNISH: How exactly are the police using these devices now?
ZOMORODI: Well, in various ways. So this device can tell what cell phones are in the area. So it's part of the president's security detail. It's on the roofs of many U.S. embassies. But as for police, as far as we know, it's being used to find criminals, and it's being used secretly. Law enforcement doesn't want the public, especially the criminals among us, to know how exactly and how often they use them because then these criminals would find ways to evade the technology. But there is evidence that Stingrays are widely being used by police departments maybe hundreds, maybe even thousands of times a year. We spoke to Chris Soghoian, a principal technologist at the ACLU, who's - he's been researching these devices. And so he describes Stingrays kind of like a game of Marco Polo.
CHRIS SOGHOIAN: So the police go to Verizon, and they say, where is this target? We're looking for this guy. Where is the? And Verizon says, we're not able to tell you exactly where he is, but we think he's, you know, within a mile of two or this place. So the police will show up there with their special surveillance van which probably won't say surveillance van on the outside, and they will start to drive around that neighborhood with the Stingray turned on and with this antenna mounted on the roof. And it'll start to send out these signals, and they'll drive it around until eventually the phone responds to their Marco signals.
CORNISH: And Manoush, when they hear the Polos - right? - the signals back from the phone they're looking for, can they zero in on it?
ZOMORODI: Yeah, exactly. That's what they do. They get closer and closer. There are even handheld versions of this so police can go door to door, inside a building. And Audie, the only reason we know this is because of a criminal who was the first to figure out that he was indeed caught by a Stingray. It's a tax-fraudster by the name of Daniel Rigmaiden, and he tells us his full, crazy story on our podcast this week. But basically, he was filing fake tax returns online using an anonymous cellular Internet air card which, by his calculation, should have been impossible to locate.
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DANIEL RIGMAIDEN: The instant I was getting arrested, when I was laying on the sidewalk getting hand cuffs put on me, I instantly knew that they had tracked the air card down. It was the only weak link in the whole operation.
CORNISH: And Manoush, on the podcast, he talks about spending his five years in prison basically researching and proving that theory. But did it affect his case? I mean, was there anything legally wrong with using these devices?
ZOMORODI: The judge ruled that using a Stingray does not count as an illegal search even though it sends signals into people's living rooms. But, you know, Audie, most judges never even discover a Stingray was used in a case because in order to use Stingray or a cell-site simulator, police departments sign a nondisclosure agreement promising not to talk about it. Now, we got a hold of an NDA which says that in some cases, the FBI could as prosecutors to drop a case rather than risk revealing details of how these devices work.
CORNISH: But has that ever happened?
ZOMORODI: It's hard to say. When we asked the FBI about this, a spokesperson emailed us back. He wrote, to date, the FBI has not required any agency to dismiss their case based on this provision in the NDA. But he did also add that they plan on using Stingrays more and more as more and more communication happens on cellular devices. And you know, I think that's the question. Are we OK with law enforcement using tech that they can't tell us about, not even in court? And should it take a convicted felon to uncover these tactics, or should there be more transparent and potentially regulated ways to make sure that devices like these are being used properly? It's the age we live in, Audie.
CORNISH: Manoush, thanks so much for sharing your reporting with us.
ZOMORODI: It was a pleasure.
CORNISH: That's Manoush Zomorodi, host of the podcast "Note To Self" from our member station WNYC. Their latest episode posted on Friday is called "Daniel Rigmaiden And The Stingray."
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