Your every move, tracked and sold. It sounds like a dystopian movie, but it's the reality for millions of mobile phone users. The government can track your location, not usually by directly spying on you, but through a complex web of data collection and sales you probably don't even realize is happening. And U.S. Immigration and Customs Enforcement (ICE) is among those buying this data.
Forget images of shadowy figures in trench coats. The truth is far more subtle and pervasive. The U.S. government often doesn't need to actively collect location data itself. Your phone is already doing the work for them. While some location data collection seems straightforward – like when you use a maps app for directions or check the weather – much of it happens silently, in the background. Think about it: every app asking for location permissions, every website you visit... it all adds up.
I'm a privacy researcher focused on how people understand and react to the collection of their personal data, and I'm constantly looking for ways to empower individuals to regain control over their privacy. But here's where it gets controversial... Once you grant an app or website permission to access your location, you essentially lose control. You have little to no say in how that data is used, who it's shared with, or whether it's sold to third parties. This is a critical point that demands attention.
So, why are our phones constantly tracking us?
There are two main reasons: It's a byproduct of how mobile phones operate, and it's sometimes required by law.
First, your phone is constantly scanning for nearby cell towers. This isn't just about making calls; it's about ensuring seamless connectivity so you can make calls or send texts quickly and reliably. Imagine needing to wait several seconds every time you wanted to send a text – that would be incredibly frustrating! To maintain a strong signal, your phone often connects to multiple towers simultaneously. This is how it determines the best signal.
And this is the part most people miss... By connecting to multiple towers, your phone's location can be pinpointed through a process called triangulation. Think of each cell tower's signal range as a large bubble. Where these bubbles intersect, that’s where your phone is likely located. The more towers your phone connects to, the more precise the location data becomes.
Second, since 2001, mobile phone carriers have been legally required to provide location information (latitude and longitude) for any phone that calls 911. This is obviously crucial for emergency services, allowing them to respond faster and more effectively. It’s hard to argue against this life-saving measure.
But how does this location data end up in the hands of government agencies and data brokers?
When you grant an app or website permission to access your location, the company behind that software can share that data extensively, often without further consent. Sometimes, apps share this data directly through partnerships with data brokers. This can be as simple as a fitness tracking app sharing your running routes with a marketing company that sells running shoes.
More frequently, location data is shared through a process called "real-time bidding" (RTB), which is used to determine which ads you see online. When a webpage or app contains advertisements, a lightning-fast auction occurs behind the scenes every time the page loads. Advertisers bid for the opportunity to show you an ad. To target the right audience, the software embedded in the app or webpage shares information about you, including your location, with these bidders. These third-party bidders act as middlemen. They can retain your data and use it as they see fit, including selling it to location data brokers, regardless of whether their bid wins the ad auction. This is a massive, largely unregulated marketplace.
Once location data brokers acquire this information, they sell it widely to various organizations, including location-based service providers. These providers repackage the data and sell access to tools that monitor people's locations. Some tools provide legitimate services like roadside assistance, but others are used by law enforcement, government agencies, and even private individuals to track people down. The implications are staggering.
In October 2025, reports surfaced that U.S. Immigration and Customs Enforcement (ICE) purchased a location surveillance tool called Penlink. This tool allows them to track the movements of specific mobile devices over time, without a warrant, accessing location data from "hundreds of millions of mobile phones". This raises serious questions about privacy and government overreach.
Why all of this matters is because location data is incredibly sensitive and, contrary to what some might claim, virtually impossible to truly anonymize. Your two most frequented locations are typically your home and workplace. With just this information, it's remarkably easy to identify you and link that identity to all the other location data these companies have collected. Imagine someone knowing where you live, where you work, your daily commute, and the stores you frequent. That's a deeply personal and revealing profile.
Furthermore, most people are unaware that the location data they allow apps to collect for one seemingly harmless purpose, such as navigation or weather updates, can reveal sensitive personal information that they wouldn't want sold to data brokers. For example, a research study I conducted showed that while people used location data to track their exercise routes, they didn't consider how that data could be used to infer their home address. This lack of awareness creates a significant vulnerability.
This means people don't anticipate that data collected through normal mobile phone use might be accessible to entities like U.S. Immigration and Customs Enforcement. This disconnect between expectation and reality is deeply troubling.
Stronger restrictions on how mobile phone carriers and apps collect and share location data – as well as on how the government obtains and uses this information – are crucial for protecting your privacy. However, efforts by the Federal Trade Commission (FTC) to curb carriers' data sales have faced challenges in federal court, and only a few states are actively pursuing legislation to address the problem. This leaves a patchwork of protections, leaving most people vulnerable.
So, what do you think? Is the convenience of location-based services worth the risk to your privacy? Should the government have access to this data without a warrant? And what steps can individuals take to protect themselves in this increasingly data-driven world? Share your thoughts in the comments below!
