The Wall Street Journal published an article recently explaining how Facebook chooses which ads to target users with — and it’s not by spying on you through your phone’s microphone.

The article published in the Wall Street Journal is titled “Facebook Really Is Spying on You, Just Not Through Your Phone’s Mic.” The article outlines a phenomenon that many people have claimed to experience — talking about a product or a destination to a friend, and a short while later receiving ads for the product or cheap flights to the destination they discussed. This leads many to believe that Facebook is accessing users’ phone microphones to listen in on conversations in order to determine what advertisements to display to them. But, according to Facebook, they do not possess the resources to analyze audio from billions of users.

Former Facebook ad-targeting product manager Antonio Garcia Martinez told the Wall Street Journal that such data analysis “would strain even the resources of the NSA.” Former Facebook operations manager Sandy Parakilas corroborated Martinez’ claim saying that Facebook “would need to understand the context of what you are saying—not just listen for words.” It seems that the reason Facebook doesn’t listen in on users via their microphones isn’t that they are particularly opposed to the idea, but because it would be a drain on the company’s time and resources. Not to mention the fact that they already have other ways of knowing exactly what to advertise to their users.

The author of the WSJ article, Joanna Stern, included the example of Facebook displaying ads for Sudafed right around the time she asked her husband to purchase some for her as she was suffering from a cold. Stern guessed that Facebook had listened to her conversation with her husband in order to suggest an ad for the medicine, but upon investigation, Stern discovered that the social media company had used another form of tracking to determine what ads they should display. Stern had previously purchased tissues and Afrin at a convenience store, where she keyed in her phone number in order to gain loyalty points at the store. Once she did this, information about her purchases was collected by a third-party data collector.

Johnson & Johnson, who produce Sudafed, then paid that data collector for the information on Stern’s purchase. This would include her loyalty card details such as name, phone number, email address, etc. meaning that Stern’s loyalty card could easily be linked to her Facebook profile. Based on this information, and other information gained from those who purchased similar products to Stern, Johnson & Johnson chose to target their Facebook ads towards adults ages 25 to 54 who bought Sudafed or a competing brand.

Facebook also has access to your location details due to settings on their Facebook app, this is used to gain a general idea of users movement and purchasing habits. If a user spends a long amount of time in a specific shop, they may see more ads on Facebook reminding them to shop there again. Users can combat this quite simply on their iPhones, just go to Settings > Account Settings > Location and turn off location tracking and location history. This should prevent Facebook from digitally tracking your every move.

Facebook also monitors which apps you spend the most time on in order to determine which ads to suggest, this is another easy fix for iOS users who simply have to navigate to Settings > Privacy > Advertising > and turn on Limit Ad Tracking. Android users can go to Settings > Google > Ads > Opt out of Ads Personalization. Facebook spokesperson Joe Osborne commented on the company’s information tracking saying “When ad targeting is used well, it makes advertising better. That’s why we build our targeting tools in a way that doesn’t share people’s personal information with advertisers and that gives people control over the ads they see.”

For those that are still worried that Facebook may be listening in on their conversations, you can disable Facebook’s access to your microphone. On iOS, go to Settings > Privacy > Microphone > Facebook and disable Facebook’s access to the microphone. On Android, go to Settings > Apps > Facebook > Permissions > Disable microphone. This should help particularly security minded individuals gain some peace of mind that Mark Zuckerberg isn’t listening in on their conversations.