Here’s the thing nobody mentions when they tell you to ‘just turn off location services.’ Your phone has multiple totally separate ways to figure out where you are, and GPS is only one of them.
The moment your phone is on, it’s already talking to cell towers. That’s just how cellular networks work — your phone has to check in with the nearest tower to know it can make calls and use data. According to the New Jersey Cybersecurity and Communications Integration Cell, this happens as soon as you power on your device, and since most people need cellular service for basic communication, turning it off just isn’t realistic for most of us.
And it doesn’t stop there. If your Wi-Fi is on, your phone is sending out signals looking for networks — even if you’re not connected to one. Every router has a unique identifier, and when your phone pings nearby routers, those pings can be logged and used to figure out roughly where you are. Bluetooth works similarly. So even with GPS fully off, your phone is still leaving a trail.
Then there’s the really clever stuff. Researchers at Princeton University built an app called PinMe that demonstrated exactly how far this goes. PinMe tracked and located people using only the data that’s still available when GPS is turned off — things like the accelerometer (which senses movement and direction), the barometer (which senses altitude), and whatever network signals the phone could detect. Combined, those data points were enough to follow someone’s movements in detail.
So what can you actually do? Turning off Wi-Fi and Bluetooth when you’re not using them does reduce your exposure. Airplane mode cuts off most signals at once, though it also kills your ability to make calls or use data. And knowing this is half the battle — because a lot of apps ask for permissions they don’t need, and understanding how tracking actually works helps you make smarter choices about what you allow.