Your cell phone may be spying on you.

Every time you download an app, search for a website, send a text, snap a QR code or drive by a store with your GPS on, you are being tracked by your cell phone company.

“They know you were playing Angry Birds. They know that you drove by Sears. They know you drove by Domino’s Pizza. They can take that and take a very unique algorithm that can focus on your behavior,” explained marketing expert Mark Johnson. “It’s very impactful.”

According to Johnson, your data trail is worth big money to the cell phone companies.

Details about your habits, your age and gender are compiled and can be sold to third parties. The information is predominantly used as a marketing tool so advertisers can target you with products or services that you are more likely to use or want.