Editor’s note: This article was first published in June 2018, after Mark Zuckerberg’s April 2018 testimony to the US Congress. Its description of how Facebook tracks users reflects that time. Facebook’s tracking tools, ad-targeting options and the wider privacy rules have changed since.
It has very probably happened to you: you are talking with a friend about something (say, going on holiday to Dubai), and suddenly ads related to it start appearing in your Facebook feed. Coincidence? Could Facebook be spying on you and listening through your smartphone’s microphone?
Given that this has happened to thousands of people, concern that Facebook listens to conversations outside its social network has grown considerably. In fact, Mark Zuckerberg himself had to state before Congress that it was not true and that it was a conspiracy theory.
A similar conspiracy theory led thousands of users to remove supposed microphones from their Samsung batteries, which turned out to be NFC antennas. A very clever discovery, by the way, considering these users never stopped to think that there is no need to hide a microphone in a battery when the phone’s own built-in microphone is a far better disguise.
It is understandable that this myth exists, above all because of how accurately ads are aimed at whatever we happen to be interested in at the moment.
Can an app really listen to you through your phone’s microphone?
The truth is that it can. Facebook could use your microphone to listen to everything you say in your daily life. But it is even more true that Facebook does not need to. In fact, it is not doing it. Mark Zuckerberg has been very candid in revealing very sensitive details about privacy and tracking for advertising purposes.
So how does Facebook target ads so accurately?
Facebook knows perfectly well how to target ads thanks to the huge amount of data it already has on you, both online and offline.
First, Facebook tracks your browsing habits through the Facebook Pixel. If you visit a website that has the “Like” button, Facebook starts tracking your browsing and shopping habits across the web.
But don’t get paranoid: if it is any consolation, Amazon, Google and dozens of other companies do it too, and they make your browsing safer and more useful. Safer, more useful, but less private.
Remember that there are plenty of free services and free content on the internet. They are free because you see ads, which is a tiny price to pay for everything you get.
How does Facebook know your interests?
The truth is that, for Facebook to be effective, it has to cross-reference its data with data collected by third parties. For example, a website with millions of visits will already have collected all kinds of data about its users, starting with a basic interest. On a car website, for instance, we already know one thing: its users like cars.
Third-party data includes age, gender, country and city. That alone can say a great deal about our personality.
For example, psychology and marketing experts now know that a person whose interests include computers is more likely to have an introverted personality, so an ad designed specifically for introverts with certain interests makes you more likely to click on it.
Think of it this way and you will see you can know as much as Facebook
Look at a Facebook profile. See which pages the person likes, what posts they share, which articles they comment on and what they say in those comments. What would you know about them? To begin with, you know whether they are a man or a woman, their age, and the country and city where they live. From the pages they like you can learn exactly what they are interested in: whether they enjoy reading, whether they like wedding dresses, whether they are straight or gay. And if you also look at their comments, you can tell whether the person is racist, xenophobic or homophobic, whether their politics lean left or right, whether they are Catholic or Muslim, and so on.
It is surprising how many people are outraged by the lack of privacy when they themselves are saying everything in public. Add to what we can all see on any profile (which is no small amount) the fact that Facebook can also see that person’s browsing on the internet, and the accuracy of targeted advertising is astonishing.
That is why Facebook does not need to listen to the conversations you have with your friends or family.
But how does Facebook know your offline shopping habits?
This is perhaps the most interesting part. Facebook has “on file” every device you have ever used the social network on, or used to browse any site that had a Facebook service (such as the “Like” button). In other words, if you have been on the internet, Facebook already has that device.
Facebook even knows which shops you have been to, because all it needs to know is where your phone has been. All of this thanks to geolocation. But, as we said earlier, it all works by cross-referencing data that different companies share with one another for a common purpose: to improve advertising and show you only ads based on your interests, increasing the likelihood that you buy.
Don’t forget the science of coincidence
When you talk with a friend about something and then come across an ad for exactly that, it may also be down to the art of coincidence or other psychological factors we have discussed in previous articles.
It is similar to when you are standing in a queue and notice that the other queue is moving faster. Let’s say we tend to look for explanations when something involves us personally. This is known as the reticular activating system. It is the system that makes you see far more pregnant women than before when you, or your partner, are pregnant.
You probably don’t notice most of the ads placed on websites, since most of them are monotonous and boring. But if you have a seaside holiday in mind, when you see an ad with a deal on a trip to the coast your eyes are more likely to lock onto it like someone spotting a glass of water in the desert, having ignored dozens of ads that were also based on your interests. Past interests.
In case there is still any doubt, the New Statesman ran a non-scientific test of whether Facebook was serving ads based on a person’s conversations and found that it was not.
What happens if a vegetarian starts telling all their friends and family that they are craving a Domino’s pizza? Nothing happened, in that case or in other similar ones. The ads were still based on interests, not on conversations.
Featured image: © Raimond Spekking / CC BY-SA 4.0 (via Wikimedia Commons), CC BY-SA 4.0, via Wikimedia Commons.
