Spy bins and passive Wi-Fi monitoring

A spy bin in London. Image source: Mona Boshnaq/AFP/Getty Images

The humble litter bin has now become a high tech device with the ability to track people's movements. The Renew ad firm has installed technology that is able to measure Wi-Fi signals in rubbish bins around London's Square Mile. According to The Guardian the advertising firm has suggested that it,

would apply the concept of "cookies" – tracking files that follow internet users across the web – to the physical world.

Renew's chief executive Kaveh Memari, it quoted as saying, "We will cookie the street."

The spy bin's ability to capture the serial numbers of smartphones and analyse signal strength in order to track people's movement's along the street, have not been without controversy and has resulted in the City of London Corporation demanding Renew to withdraw the program.

The data captured from these devices could have potential uses for advertising. For example, the Sydney Morning Herald, suggests that if it enabled companies to see how long people spent in particular locations each day, commercials could be targeted towards individuals:

But if a company could see that a certain smartphone user spent 20 minutes in a McDonald's every day, it could approach Burger King about airing an ad on the bin's video display whenever that user walks by at lunchtime. Or it could target its commercials in real time by distinguishing between people who work in the area and visiting tourists.

Such surveillance has drawn comparisons with the 2002 film Minority Report and raises important questions about privacy as well as public awareness of the extent to which their movements are being watched. The City of London Coporation, who according to The Guardian, only discovered the use of the spy bins via the press, released a statement noting that "Anything that happens like this on the streets needs to be done carefully, with the backing of an informed public".

The spy bins are being investigated by Britain's data protection watchdog, while the privacy advocate group Big Brother Watch, is urging that questions should be asked  "about how such a blatant attack on people's privacy was able to occur".

Renew chief executive, Memari, released a statement in response to the media interest which he described as being a bit breathless, and commenting on the future potentials of the spy bins:

"A lot of what had been extrapolated is capabilities that could be developed and none of which are workable right now."

But Wi-Fi tracking of smartphone users is not just restricted to rubbish bins. The Economist reported that American fashion retailer, Nordstrom trialed a system that tracked smartphone users as they moved through its stores or walked nearby. The firm did post a public notice about the system, and withdrew the program when it was covered by a Dallas-based television channel. The New York Times was next to take up the story prompting a privacy debate around passive monitoring.

Nordstrom, and several other companies used a system provided by Euclid Analytics, which can track precise movements of phones without having to connect to Wi-Fi networks. According to The Economist,

The technique takes advantage of the fact that Wi-Fi wireless networking protocols are "promiscuous": the Wi-Fi adaptors in laptops, phones and base-stations reveal a lot of information about those devices as they attempt to negotiate connections with other devices nearby. Even before a device hooks onto a Wi-Fi a network, it continuously spews identifying information, including a unique, factory-set identifier, over the air. Most devices send "probe requests" akin to a town crier shouting out the names of networks which the device has previously connected to, so that a nearby base-station that matches any of these requests can respond. The requests run unremittingly across all available frequencies until a connection is made. Even devices that are seemingly turned off, such as sleeping laptops, send out such probes, though at a slower rate. Place several Wi-Fi base-stations in a shop, then, and you can pick up these probe requests, extract the device IDs, trilaterate the positions of the devices sending them, and thus track the movements of individual shoppers, seeing which racks or displays they stop at, and what paths they follow through the store.

The Economist notes that this is just the next step in the evolution of "retail science", which analyses the movements of shoppers and assists retailers in determining where to best place products and displays. While this used be done by video, Wi-Fi allows more accurate tracking. This concerns privacy advocates because despite, signs notifying them of the tracking, the increasing strength of Wi-Fi means that passers by can also be detected. They also note the possibility that monitoring systems could collect the list of known networks on an individual phone and use it to find out further details including place of work or residence about the phone user, from which individual identities can be plausibly be deducted.

After the New York Times article, Euclid and other firms announced they had joined forces with the Future of Privacy Forum, to create a group focused on developing best practices for retail location analytic's companies. Commenting on the new group, Euclid co-founder and CEO, Will Smith, noted, 

“New technologies are helping retailers better understand what customers want and make shopping more convenient for everyone ... Privacy has always been a priority as we’ve designed and built our services, and we are excited to work with FPF to develop best practices for the retail analytics industry.”

Monitoring smartphone user's location via Wi-Fi may help advertisers and retailers but issues of privacy invasion via these systems must be addressed. And this goes beyond purely location to the data that can be extrapolated from movement patterns. Bradley Voytek, a neuroscientist quoted in The New York Times article notes, “The creepy thing isn’t the privacy violation, it’s how much they can infer.”

The following video explains why and how bricks and mortar shops are using Wi-Fi tracking to monitor customers activity in order to keep pace with online vendors.

Future of Privacy Forum director, Jules Polonetsky maintains that,

“Companies need to ensure they have data protection standards in place to de-identify data, to provide consumers with effective choices to not be tracked and to explain to consumers the purposes for which data is being used ... By being transparent about what is going on, location companies and retailers can make sure shoppers understand the benefit of the bargain."

And considering the spy bin incident, this applies just as much to Wi-Fi monitoring on the street as it does inside retails stores.