Your apps could be collecting precise details on where you are, all day long.
A recent study shows the average smartphone user's location data was tracked more than 3,000 times in one week. That's more than 400 times per day.
One company called Mist developed new location data-gathering technology to track users through hotels, museums and even shopping malls.
Using Mist's invisible Wi-Fi and Bluetooth sensors, a retailer can access your phone to send you coupons the minute you walk in the door. A museum might push facts about a piece of art.
So how can you keep your whereabouts more private? Read more from NBC Los Angeles.