When you make a voice call on your smartphone, the information is protected: Your phone company can’t sell the fact that you are calling car dealerships to others who want to sell you a car. But if the same device and the same network are used to contact car dealers through the internet, that information — the same information, in fact — can be captured and sold by the network. To add insult to injury, you pay the network a monthly fee for the privilege of having your information sold to the highest bidder.