© Illustration by Alex Castro / The Verge

US government officials are using cellphone location data from the mobile ad industry —not data from the carriers themselves— to track Americans’ movements during the coronavirus outbreak, the Wall Street Journal reports. The Centers for Disease Control and Prevention, along with state and local governments have received cell phone data about people in areas of “geographic interest,” the WSJ reports.

The goal is to create a government portal with geolocation information from some 500 cities across the country, to help ascertain how well people are complying with stay-at-home orders, according to the WSJ. One example of how the anonymized data was reportedly used: Researchers discovered large numbers of people were gathering in a New York City park, and notified local authorities.

The use of even anonymized data raises myriad privacy concerns, with privacy advocates urging limits on how such data can be used and prevent its use for other purposes, the WSJ reported.

Other countries have used cell phone data to track citizens’ movements during the pandemic; mobile carriers in the European Union have reportedly shared some data with health authorities in Italy, Germany, and Austria. although details about specific patients were not included. Israel authorized the use of cellphone location data to track the virus, with data to be used in a “focused, time-limited and limited activity,” according to The New York Times.



China’s tracking system sends information to law enforcement officials, while Taiwan’s “electronic fence” alerts authorities when a quarantined person moves too far away from their home. And South Korea used cell phone location data to create a public map of coronavirus patients, to track where people may have been exposed.

Cell phone carriers in the US told the WSJ that have not been asked by the government to provide location data. But the Washington Post reported on March 17th that the federal government was in “active talks” with Facebook, Google, and other tech companies, to figure out how to use location data from phones.