Next time you go shopping, know this: The stores you visit may be using your cellphone to track your movements. Nordstrom started the trend by digitally following the Wi-Fi signals from customer smartphones. But after customer complaints, they shut it down. However, there are plenty of other stores that have jumped on the bandwagon.  

So how do they track us? Your phone’s signal is unique, so the minute you step in a brick-and-mortar store, they know exactly who you are, when you were there last and can immediately offer ads and coupons based on your previous shopping patterns.  

An increasing number of stores, including Benetton and Family Dollar, are gathering data about the behavior of in-store shoppers.  The store can see, for example, that 70-percent of shoppers turn right when they enter a store. And they linger 14-percent longer in front of a fancy display than regular shelves. 

Stores can see how many minutes people spend in the candy aisle and how long we look at merchandise before buying it. Stores can also see which aisles are the busiest and figure out when they should open more cash registers or have more employees on duty. They can even monitor the happiness levels of shoppers using facial recognition.

So what do you think? Is it okay to give up some privacy to get store discounts? Or is tracking your movements in stores too invasive? Weigh in at Facebook.com/JohnTesh. 

And if you don’t want to be tracked, put your phone in “airplane mode” before you enter the store. Because the way they know you’re there and who you are is by your phone searching for a network signal or WiFi.