Entries Tagged "geolocation"

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Google Receives Geofence Warrants

Sometimes it’s hard to tell the corporate surveillance operations from the government ones:

Google reportedly has a database called Sensorvault in which it stores location data for millions of devices going back almost a decade.

The article is about geofence warrants, where the police go to companies like Google and ask for information about every device in a particular geographic area at a particular time. In 2013, we learned from Edward Snowden that the NSA does this worldwide. Its program is called CO-TRAVELLER. The NSA claims it stopped doing that in 2014—probably just stopped doing it in the US—but why should it bother when the government can just get the data from Google.

Both the New York Times and EFF have written about Sensorvault.

Posted on January 28, 2020 at 6:53 AM • View Comments

Facebook Using Physical Location to Suggest Friends

This could go badly:

“People You May Know are people on Facebook that you might know,” a Facebook spokesperson said. “We show you people based on mutual friends, work and education information, networks you’re part of, contacts you’ve imported and many other factors.”

One of those factors is smartphone location. A Facebook spokesperson said though that shared location alone would not result in a friend suggestion, saying that the two parents must have had something else in common, such as overlapping networks.

“Location information by itself doesn’t indicate that two people might be friends,” said the Facebook spokesperson. “That’s why location is only one of the factors we use to suggest people you may know.”

The article goes on to describe situations where you don’t want Facebook to do this: Alcoholics Anonymous meetings, singles bars, some Tinder dates, and so on. But this is part of Facebook’s aggressive use of location data in many of its services.

BoingBoing post.

EDITED TO ADD: Facebook backtracks.

Posted on June 28, 2016 at 6:56 AM • View Comments

Analysis of Yemeni Cell Phone Metadata

This research shows the power of cell phone metadata. From an article by the author:

Yemen has experienced an array of violent incidents and political turmoil in recent years, ranging from al Qaeda militant attacks to drone strikes, Arab Spring protests, and now Saudi Arabian air strikes. Call patterns can capture political or violent activities as they unravel in real time. For instance, there was a significant increase in the number of local calls following a nighttime drone strike on Friday, October 14, 2011, in Shabwa Province, which killed Ibrahim alBanna, media chief of al Qaeda in the Arabian Peninsula, along with eight others. Several additional drone strikes are detectable through significant spikes in local call volume at the time of attack, including a May 5, 2011, strike in Jahwa that killed two brothers affiliated with al Qaeda. A May 10, 2012, attack that killed eight al Qaeda militants in Jaar and a May 25, 2010, attack in Wadi Abida that killed two militants and four to six civilians.

Because call data records are geolocated, researchers can also examine them to assess users’ mobility. This can be a very useful tool to detect protests and other events that entail notable mobilization. On Friday, June 3, 2011, for example, the day President Ali Abdullah Saleh was attacked at the presidential palace in connection with the Yemeni Arab Spring, the number of people near the palace spiked around the time of the incident. Several other protest events linked to the Yemeni Arab Spring are captured by high levels of user mobility, including the string of Friday protests during 2011 when protesters would gather at Sanaa University Square and government supporters would stage their counterrallies at Sanaa’s Tahrir Square.

From an interview:

So for instance, if you are interested in larger political patterns, such as who shows at a demonstration, or who takes a leadership role in a demonstration…by having this data, you know what he’s like. You know where he lives. You know who he calls and who his friends are. You know if he’s Shia or Sunni, depending on what holidays he makes calls. You know if he’s rich or poor depending on how much phone credit he uses.

Posted on March 13, 2016 at 6:32 AM • View Comments

Determining Physical Location on the Internet

Interesting research: “CPV: Delay-based Location Verification for the Internet“:

Abstract: The number of location-aware services over the Internet continues growing. Some of these require the client’s geographic location for security-sensitive applications. Examples include location-aware authentication, location-aware access policies, fraud prevention, complying with media licensing, and regulating online gambling/voting. An adversary can evade existing geolocation techniques, e.g., by faking GPS coordinates or employing a non-local IP address through proxy and virtual private networks. We devise Client Presence Verification (CPV), a delay-based verification technique designed to verify an assertion about a device’s presence inside a prescribed geographic region. CPV does not identify devices by their IP addresses. Rather, the device’s location is corroborated in a novel way by leveraging geometric properties of triangles, which prevents an adversary from manipulating measured delays. To achieve high accuracy, CPV mitigates Internet path asymmetry using a novel method to deduce one-way application-layer delays to/from the client’s participating device, and mines these delays for evidence supporting/refuting the asserted location. We evaluate CPV through detailed experiments on PlanetLab, exploring various factors that affect its efficacy, including the granularity of the verified location, and the verification time. Results highlight the potential of CPV for practical adoption.

News articles.

Posted on February 12, 2016 at 6:19 AM • View Comments

Fugitive Located by Spotify

The latest in identification by data:

Webber said a tipster had spotted recent activity from Nunn on the Spotify streaming service and alerted law enforcement. He scoured the Internet for other evidence of Nunn and Barr’s movements, eventually filling out 12 search warrants for records at different technology companies. Those searches led him to an IP address that traced Nunn to Cabo San Lucas, Webber said.

Nunn, he said, had been avidly streaming television shows and children’s programs on various online services, giving the sheriff’s department a hint to the couple’s location.

Posted on July 29, 2015 at 1:43 PM • View Comments

Geotagging Twitter Users by Mining Their Social Graphs

New research: Geotagging One Hundred Million Twitter Accounts with Total Variation Minimization,” by Ryan Compton, David Jurgens, and David Allen.

Abstract: Geographically annotated social media is extremely valuable for modern information retrieval. However, when researchers can only access publicly-visible data, one quickly finds that social media users rarely publish location information. In this work, we provide a method which can geolocate the overwhelming majority of active Twitter users, independent of their location sharing preferences, using only publicly-visible Twitter data.

Our method infers an unknown user’s location by examining their friend’s locations. We frame the geotagging problem as an optimization over a social network with a total variation-based objective and provide a scalable and distributed algorithm for its solution. Furthermore, we show how a robust estimate of the geographic dispersion of each user’s ego network can be used as a per-user accuracy measure which is effective at removing outlying errors.

Leave-many-out evaluation shows that our method is able to infer location for 101,846,236 Twitter users at a median error of 6.38 km, allowing us to geotag over 80% of public tweets.

Posted on March 10, 2015 at 6:50 AM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.