It's not just the stuff of TV dramas or movies. You may think no one's watching; that you're on your own, but as long as that smartphone is on and in your pocket you're never quite alone.
[WEB EXTRA: How to change privacy and location settings]
If you have an iPhone it's Apple. On an Android, it's Google.
"You want to think no one's watching you, but apparently that's not the case. So it is creepy," said Marie Jeanrejouis who uses an iPhone.
If you look buried in your iPhone settings you'll find a detailed history of where you've been, how often they've been there, and it's time stamped down to the minute they were there.
And on a Droid, it's even more detailed, and it's all plotted on GoogleMaps.
GPS and Wi-Fi networks pinpoint your every move from home to work and back your phone sends all that information back to tech companies.
"Companies have a vested interested in figuring out where you are and what you're doing," explained Mary Dickerson who heads the IT department at the University of Houston. She says your information helps companies make money. But there's no 100 percent guarantee Apple and Google can keep it safe.
"There's always a risk the question is, is it a significant risk," said Dickerson.
So can you stop the tracking? Yes.
On a Droid just go to settings, select location services and uncheck GPS and Wi-Fi.
On an iPhone it's a bit more complicated. Go to settings, click privacy, then select location services. Scroll down to system services. That's where you find frequent locations. Just turn that feature off.
But there's a catch. Even after all that your cell phone provider can still keep tabs on you.
To completely go off the grid your only option is dumping your smart phone.