Conspiracy theorists think Facebook has tapped your phone's microphone to target ads by listening to your conversations. Truth is, it doesn't have to. WSJ’s Joanna Stern explains how Facebook and its advertisers really keep tabs on you.
That eerily relevant ad in your Facebook news feed? It’s a result of all the data you’ve given Facebook and advertisers. Facebook is now so good at watching what we do online—and even offline, wandering around the physical world—it doesn’t need to hear us to know what we like. Here are some ways to limit the amount of data Facebook and advertisers are collecting about you."