We all know that our phones and apps keep tabs on our locations—and it feels like most of us have come to terms with the fact that way too much of this data makes it into the hands of companies that want to advertise to us. The problem? No one really thinks about how that data is actually being stored, or how anonymous it isn’t.

According to a recent investigation by The New York Times, the data collected by the devices, apps, services, and websites we use gets passed along to a handful of private data-collection companies, who then funnel it into massive databases.

The Times was given access to one such file that included data on over 12 million devices from 2016 to 2017, representing a total of more than 50 billion individually pinged geographic locations. All of these locations can be easily pinpointed on satellite maps, and they include...well, everywhere: celebrity homes, secure government facilities like the Pentagon, and just about every major city or public location you can think of.

Despite being stripped of all personally identifying information, the Times found that a person can still isolate and view the data of a single device if you know even a reasonable amount about a person. If you have access to one of these files and information about the specific location of someone’s device at a given time, you can acquire that device’s entire location history. Yikes.

How to prevent your location data from being tracked

The full article is worth the time to read, as it explains just how this data is collected, how it’s accessible by employees of these companies, and why it’s so often shared with even more companies. (Spoiler: advertising).

However, the real issue is how many potential privacy and safety concerns are built into these giant databases of location histories. It’s easy to imagine scenarios when hackers, stalkers, or even entire political agencies could use this information maliciously.

While it’s going to take herculean legislation to enforce limits or otherwise restrict data collection, and how location data is used and shared, there are a few things you can to do to try and reduce the firehose of information you’re sharing to a trickle. Here are several suggestions we recommend trying:

• First, and most importantly: Turn off your phone’s location tracking
• Keep tabs on which apps track your location (and other data)
• Use desktop and mobile web browsers that don’t track your data. Firefox, Brave, Vivaldi, Tor, and Opera all combat data-collection in various ways
• Use privacy settings like incognito mode in Google maps and other apps
• Review app permissions and revoke any that seem unnecessary. Don’t be afraid to delete apps that ask for too much: a ruler app probably doesn’t need to track your location, for example
  
• Limit advertising tracking in your smartphone whenever possible (iOS, Android)
• Review and delete any data that is stored by Google, Facebook, Apple, Amazon, or other companies. And amp up your social media privacy, too
  
• Try to use open-source software, websites, and services that prioritize decentralization, user privacy, and encryption, whenever possible.
• For those seeking a more drastic approach, you can also try leaving big companies like Google or Apple behind—though that’s easier said than done.