When you download a new app, it will almost always ask you to turn location services on.

And therein, lies a problem. One recent survey found that 75 popular apps then sell location data to third parties once you download them.

This is why you’ll start seeing ads for a new store you’ve visited just after you leave.

The easiest way to keep your data safe is to go to your phone’s settings and turn off location services on some of your apps.

And here’s one other piece of advice. With weather and GPS apps, make sure that you only allow location services when you’re using the app.