It's the conspiracy theory that won't go away - and with good reason. Everyone I speak to these days has a story about Facebook "listening in" to their conversations.

They'll be discussing something relatively obscure that they haven't ever searched for online and, hey presto! Within hours, an advert for that exact product pops up in their news feed.

I tend to be fairly sceptical about these stories. After all, the suggestion that Facebook is secretly wiretapping all of its 2.38 billion customers to deliver targeted ads seems a little far-fetched - not to mention illegal.

But then it happened to me.

We met up for a drink in the pub and I was telling him about my visit to a kitchen designer, and his suggestion that we should have a two-tone kitchen with pale grey cabinets and a dark blue island.

This was just a casual conversation. Neither of us looked up any pictures or typed anything into our phones.

Then a couple of hours later, I got a message from the same friend, who was freaked out by an ad that had just popped on Instagram (which is owned by Facebook):

"Freaky - but this kitchen ad popped up on my Instagram after we'd been talking about your kitchen ideas," he said. " Big Brother is watching."

I should add that this friend has no plans to do up his own kitchen, so there's no reason he would be searching for anything related to kitchen design.

A little unsettling to say the least.


More than a coincidence?

As it turns out, this experience is incredibly common. After a Mirror article on the topic went viral a couple of weeks ago, we asked readers to send in their stories, and we were deluged with responses.

"I was talking to my father a few weeks back about how I was thinking about purchasing a battery charger to replace the broken one that we previously used," wrote one reader, Ian.

"I never searched for the item or anything like that. Just spoke about it.

"No more than 15 minutes later I get on to check facebook, and there are numerous ads for battery chargers popping up in my feed.

"I was sincerely disturbed by this and wondered how it could happen. The only conclusion that i could formulate was that I was being spied on via audio."

Lots of people have experienced something similar

Another reader, who goes by the screen name BrokenGothDoll, had a similar experience:

"Changing the bed a few weeks ago, I said to my husband I would eventually get round to buying some hard wearing fabric to cover the base of the bed with, because ours has been badly shredded by our cats," she said.

"Within 48 hours I was getting adverts on my Facebook feed for elasticated 'skirts' that fit round the base of your bed! I hadn't searched. I had no idea such a thing existed.

"I said to my husband 'I see you have been searching for something to cover the base of the bed'. He hadn't!"


Another reader, Carolyn, said the same thing happened to her.

"Last year, a friend from Western Australia was visiting (we live in Queensland, a good 4 1/2 hours flight away). We do not see each other often. Maybe once in 3-4 years," she said.

"Anyway, my FB ads are normally pretty predictable. Women's and children's clothing, toys, disability related stuff, etc. All things that could easily be traced to pages I visit and things I talk about.

"But then my friend and her husband mentioned they were looking at motorbikes. Something I have absolutely 0 interest in.

"Low and behold, within 2 days I was seeing ads for motorbikes, helmets etc. a few days later they went home, and I have never had such an ad show up again. 

"Coincidence? Who knows. But to me it was just plain spooky..."

Facebook's response

Facebook chief executive Mark Zuckerberg denies spying on users

The theory that Facebook is using users' smartphone microphones to listen in to their conversations and target them with ads has been around for years.

But despite the mountains of "evidence", Facebook has always categorically denied it.

"Facebook does not use your phone's microphone to inform ads or to change what you see in News Feed," the company's statement reads.






Could Facebook be lying?

The fact is that if Facebook - a company with vast technical resources at its disposal - wanted to listen in to users' conversations via their smartphones, it would be fairly trivial for it to do so.

"When one technically looks at the software code of the applications, we can see that everything is 'on' and ready to be used," Vitor Jesus, Associate Professor at the Centre for Cybersecurity at Birmingham University, told Mirror Online.

"The technology of understanding spoken word is also mature enough to be used in a simple app, (think Alexa)."

The technical capability exists

However, just because the microphone is on, that doesn't mean voice recordings are being sent to Facebook's servers for further processing.

As Facebook points out, there are plenty of legitimate reasons for using the microphone, such as recording a video or making voice calls in Messenger.

The question is whether Facebook would be willing to put everything on the line in order to gather this voice data.

"When a private stock market listed company like Facebook issues a denial, it knows the implications to its shareholders and the authorities if at a later date, it is shown to be untrue," said Kevin Curran, senior IEEE member and professor of cybersecurity at Ulster University.

"The risks are simply too great. They also do not need to do it and they have other sources of information to produce targeted ads."


From a practical point of view, voice data collection on this scale would also be a nightmare for Facebook, according to Paul Bischoff, privacy advocate at

"If you were to run network traffic analysis on data being sent to and from Facebook on a phone, there's nothing out-of-the-ordinary as far as audio transmission," he said.

"Considering audio recordings have to be uploaded to the cloud to be processed and require significantly more data than plain text, if Facebook were always recording for this purpose, we would all hit our monthly data caps in a matter of days."

6 friends at a pub with phones, all online, having a good time
Would Facebook really put everything on the line for this?

So what's really going on?

While experts agree that Facebook probably isn't using your phone's microphone for ads, the truth of what's going on is arguably just as creepy.

"For starters, every phone/computer has an IP address - this gives away where you live (country and city). And from there, using statistics, and clever logic, marketers can have many insights into your life," said Ariel Hochsatdt cyber-security expert and co-founder of VPN review website vpnMentor.

"There are more ways your browser gives you away. One of the biggest - and sometimes creepiest - ways is called cookies.

"A cookie is a tracking code that is planted on your mobile browser when you enter a website. Then, using the cookie, marketers can show you ads on other platforms (for example - Facebook or Google).

"This is why you sometimes see ads on social media for a certain store minutes after you visited their website."

But there are more sophisticated (and shadier) uses for cookies.

"For example, in a 'You Might Also Be Interested In' section on a website, you see an article titled '10 Things HR People Must Know Today'," said Hochsatdt.

"If you are interested in HR, you might click on that article - and voila! You have a cookie on your computer that brands you as a HR person. That company can then target you with ads for HR."

Young woman using a mobile phone (Pic: Getty Images)
Think before you click

Your browser history also gives you away in other ways.

For example, if you view Fireman Sam videos on YouTube, you probably have children around the ages of 3-5, so expect to be bombarded with ads for children's toys.

Your likes on Facebook also help marketers construct a profile of you and target you with ads.

For example, let's say you are a dog owner. You've probably liked Facebook pages related to dogs (local pet food stores or a vet's page, or a page sharing cute images of puppies).

Marketers can create ads targeted at people and their friends who liked those pages, so you'll be shown ads geared for dog owners.

"Basically, everything that you do online is tracked, stored, and analysed," said Hochsatdt

"As big data, machine learning, and statistical tools are becoming more and more sophisticated, so are the ways marketers can tailor ads specifically to you."


'But I haven't searched for anything'

While most of these tracking techniques might sound pretty obvious, some of the information that Facebook collects may come as more of a surprise.

Following the Cambridge Analytica scandal last year, Facebook was forced to disclose all the ways it records information on users, helping to shed light on the sheer scale of its monitoring machine.

Facebook collects a vast amount of personal data

Depending on your settings, this could include GPS location, camera information, call and text logs, and data about your device such as battery level, signal strength, and available storage space.


One theory is that, in the same way friend suggestions sometimes pop up when you've crossed paths with another user, the ads you see may be affected by the people you hang out with.

"Having done some digging and speaking to those in the know, the simple truth is that Facebook knows you far better than you think," said Andy Barr, social media expert and head of

"It knows where you are, where you have been and who you have been chatting to (if you both have the Facebook app on your phone).

"On top of this, it uses artificial intelligence and machine learning to build up a picture and profile of its users, and this is so advanced that it can serve up ads that are creepily accurate."


What about other tech companies?

Facebook may deny collecting voice data to serve ads, but that doesn't mean other companies aren't doing it.

One of the biggest tech trends of the past couple of years has been the adoption of voice-controlled technology, such as Amazon Alexa and Google Assistant.

Google Home is powered by the company's smart 'Assistant'

While home assistant microphones are always on, they do not do anything with your voice until you say the 'wake word', which is usually just 'Alexa' or 'OK Google'.

After you speak the wake word, they start recording, and then send these clips away to the cloud, where they stay until you delete them.

Last year it emerged that Amazon had filed a patent, examining the possibility of eavesdropping on conversations held around its voice-activated devices, in order to better suggest products or services to users.

"If the user mentions they would like to go to a restaurant while on the phone, a recommendation might be sent while the user is still engaged in the conversation that enables the user to make a reservation at the restaurant," the patent states.

However, the company said that the patent was a proposal for the future, rather than a feature it is preparing to roll out.

"Like many companies, we file a number of forward-looking patent applications that explore the full possibilities of new technology," it said.


Amazon Echo Dot

Derek Roga, chief executive of EQUIIS Technologies, said that the ability of these devices to record and interpret voice information was something that other companies might benefit from in the future.

"In an era of on-going cutting edge innovation when it comes to voice technology, it’s not outside the realms of possibility that other platforms are listening too and using data captured for a broader commercial benefit," he said.


What can you do to protect yourself?

The General Data Protection Regulation (GDPR), which came into force last year, requires companies to disclose what data they collect and how they use it - and obtain explicit consent to do so.

However, privacy policies are often either too vague, or companies just openly say “we may collect everything” in an attempt to cover their backs.

There are a couple of measures you can take to minimise the data sent about you - such as surfing the web in incognito mode, clearing your cooking history at least once a week and using a VPN to anonymise your surfing activity and hide your IP address.

If you're still convinced Facebook is "listening in", it is also possible to turn off the microphone in each individual app in your smartphone's settings.