Facebook spies on us but not by recording our calls. Here's how the social network knows everything

It's a given that Facebook is listening in on our conversations, right?

That's how the social network can follow up on our real-world conversations about products with ads that show up in our News Feed. 

Wrong, says Gennie Gebhart, a research director for the Electronic Frontier Foundation, who has studied Facebook's targeting efforts. 

"They don't have to listen," she says. "For Facebook to use voice detection, to find keywords and then map them onto ad preferences, that’s Stone Age targeted advertising technology. There’s much more nefarious and evasive methods and much more invisible methods available to them." 

She mentions location tracking as a case in point. This is the feature in which Facebook  “can tell who you are and what you’ve recently purchased,” she says. 

“Maybe you’re in an airport, lingering in front of an ad, and that signals to an advertiser that you might be interested in the product. Or you’re in a bar, watching a TV show and you get an ad for the TV show. Location services knows you’re in a bar where that show might be popular.”