Our old tweets can provide accurate information about the location from which they were published. An international group of researchers has just discovered that publications that include a location give much more information than we think and are trying to take advantage of it.
Specifically, they have developed an algorithmic tool that uses the information collected by Twitter to automatically predict the place where they live, where they work, where they buy or where a specific user prays. And it does it with an accuracy of more than 90 percent.
The tool, called LPAuditor (Location Privacy Auditor), exploits what researchers consider an "invasive policy" implemented by Twitter in 2009 when it incorporated the ability to tag tweets with a location.
For years, users who geographically tagged their publications with any location, even with generic information such as "Barcelona" or "New York," were also unknowingly providing their precise GPS coordinates. These coordinates were not shown on Twitter or their followers, but the GPS information was included in the metadata of the tweet and could be accessed through the Twitter API.
Twitter did not change this policy in its applications until April 2015. Currently, users of the network can choose if they share their precise location. As they explain from Twitter, only a very small percentage of people do it. But the GPS data people shared before the update remains available through the API until today.
With this information and the LPAuditor tool, researchers can now predict the place where we live or work, and the places we frequent in our free time, such as a church or something more private, as if you have frequented a certain strip club or assisted to rehabilitation.
Researchers have developed the tool to analyze those geographically labeled tweets and infer detailed information about the most sensitive locations of people. The document that will be obtained from the research will be presented at the Network and Distributed Systems Security Symposium next month.
A member of the Twitter Integrity team assured Wired that sharing location data on Twitter has always been voluntary and that the company has always provided users with a way to remove that data in their help section. "We recognized in 2015 that we could be even clearer with people, but our general perspective on shared location has always been that it is voluntary and that users can choose what they do and do not want to share," he says.