Cutting Edge Is The <i>Last</i> Place A Retailer Wants To Be, In Terms Of Tracking Mobile Shoppers

Attorney Mark D. Rasch is the former head of the U.S. Justice Department's computer crime unit and today serves as Director of Cybersecurity and Privacy Consulting at CSC in Virginia.

The ongoing debate about how far retailers can—and should—go when tracking customers through their mobile devices is getting confused, thanks to the illegal misinterpretations made by some of the vendors pushing these approaches.

Let's be clear: Be ahead of the curve in tracking consumers, and do it before case law and legislation have a chance to play themselves out, and you could find yourself with legal headaches for years—potentially having to somehow remove all of that ill-gotten data from your systems.

The most prominent player in this space is U.K. vendor Path Intelligence, which had planned to launch its FootPath system in two U.S. malls on Black Friday. But it abandoned the effort after major pushback from a U.S. senator.

FootPath relies on the provisions of Federal Law 18 USC 2511(2)(g)(i), for the proposition that it is not illegal to measure signaling information and infer a person's location. That provision, which is part of the wiretap law that makes it a crime to intercept people's communications, notes that it is not illegal "to intercept or access an electronic communication made through an electronic communication system that is configured so that such electronic communication is readily accessible to the general public." Sounds good, no? These impulses are configured in a way that is accessible to the general public, right? Anyone can capture them.

The problem here is that this particular statute was aimed at the interception of the contents of communications—wiretapping. Eavesdropping. Listening in. And the FootPath system makes a sensible exception to the wiretap law. If you are on the FM radio, then listening to the conversation ain't illegal. Same is true for things like walkie-talkies, FRS band radios, Ham radios or other services that are "configured so that the communication is readily accessible to the public." In the case of my cell-phone signals, I doubt that I have configured the device so that any communication is readily accessible to the public.

What the FootPath technology appears to do is pretend to be half a cell tower (the receiving half) and capture, record and measure the signaling information from the consumer's handset. Here is where the company likely ran afoul of the law. Federal Law 18 USC 3121 makes it illegal to install or use either a "trap and trace" device or a "pen register." Under the statute, "the term "pen register" means a device or process which records or decodes dialing, routing, addressing or signaling information transmitted by an instrument or facility from which a wire or electronic communication is transmitted. A "trap and trace device" is a device or process which 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, provided, however, that such information shall not include the contents of any communication.

Because the FootPath technology records signaling information transmitted by an instrument [telephone], it is likely a "pen register," for which a court order is required. As such, using the information gained through it without a pen register order is likely illegal.

As a side note, the FBI actually had a clever idea to use a technology very similar to FootPath. Rather than subpoenaing phone companies or others for information about the location of a particular subscriber's phone, the bureau used a technology called "Stingray" (among others), which mimics a cell tower and sends a signal to the targeted phone. The strength of the signal back would determine the location. Unlike getting information from the phone company (which would require either a subpoena or a warrant), this technology would only require the lower standard of a "pen register"—that is, a certification by the government that the information is relevant to some investigation. Now unlike FootPath, Stingray identifies a specific phone and actively "pings" that phone to determine its location. Nevertheless, both Stingray and FootPath are, under the law, "pen registers." Therefore, you need a court order to monitor their results.The purveyors of such technology have also argued that shoppers have no "expectation of privacy" as they shop in the mall and that this technology is "no more intrusive than having shoppers followed as they shop." After all, there are cameras all over the mall that can track traffic.

First, there is a difference between monitoring traffic and monitoring individuals. Second, yes, this is as intrusive as following individual shoppers around at the mall. And just as creepy. A notice at the mall is not enough to provide "consent," especially where the only way to opt out of this monitoring is to either not shop or not have a cell phone—neither option is too attractive.

And yes, Google tracks a lot of information when you shop online. But there are ways (anonymizers, for example) to mask some of this information. Plus, two wrongs don't make a right. In the end, the FootPath technology is of questionable legality and of even more dubious practicality. The market place has spoken, and the malls have responded. That's why you have a full-fledged privacy review of any new technology before you deploy it!

Do consumers (or anyone else) have any expectations of privacy in their locations or activities while they are shopping in a public place? What technologies are appropriate for collecting and storing information about consumer behavior? Can we use cameras, facial recognition, data mining or other tracking programs? How do we compare expectations of privacy in "public spaces" like shopping malls with the types of behavioral activity routinely collected and used by companies like Google and others online? Is it legal to collect this information? Like everything else in life and law, it depends.

OK. First and foremost, is what the FootPath system was proposing to do in the United States legal? My answer is, probably not. Recognize that laws related to collection and use of electronic information—particularly from telecommunications providers—is murky at best. You have the federal and state wiretap laws, each with different requirements and definitions. You have the "stored communications" act, relating to the collection or interception of stored communications. You have a variety of state laws, such as those in California, Utah, Minnesota, Florida, Oklahoma, Hawaii and Pennsylvania, that prohibit the installation and use of "tracking devices." You also have the federal "pen register" and "trap and trace" statutes, which prohibit the installation and monitoring of such devices without either a warrant or some legal exception.

To understand whether FootPath is "legal" you first have to understand what the technology does (and what it does not do) and who is using it. The technology appears to just listen to and record the signal strength of any cell phones that come within range. From the signal strength, the device can determine that there is a phone within range, the carrier (because different carriers use different frequencies) and, through the process of "triangulation" (examining signal strength to three different antennas), the location of that phone at any time it is within range of the monitoring system. It does not appear to record the phone number or other identifying information about the phone (the Electronic Serial Number or the International Mobile Equipment Identity [IMEI] number). It does not record the contents of calls, texts, E-mails or anything transmitted over the network. It just measures signal strength of the transmitter inside the phone, and from that it infers location. Clearly, the technology must also have a way to identify a particular phone once it is in range (so it can track that phone throughout the mall). But this does not mean that the technology knows in any meaningful way who owns the phone. Well, at least not yet.

The signal strength is continuously "broadcast" by your cell phone and is not encrypted (nor could it be, because it is not content). The Footpath technology could be "active"—that is, "pinging" all phones within range, or "passive"—that is, just looking for a signal. Either way, it is just measuring ambient radiation broadcast throughout the mall. You don't have a "reasonable expectation of privacy in the strength of you cell phone's transmissions." Or do you?

If you disagree with me, I'll see you in court, buddy. If you agree with me, however, I would love to hear from you.