A long-held conspiracy theory – that Facebook is listening in on conversations to target us with adverts – has resurfaced again on social media.

One of Facebook’s executives in charge of adverts responded to a tweet from PJ Vogt, co-host of the internet-focused Reply All podcast, who asked followers to phone in if they believed Facebook had used their phone microphone to spy on them for advertising purposes.

The social media site’s Rob Goldman quickly responded to categorically deny such activity takes place on Facebook’s family of apps, which also includes Instagram.

The original theory dates back some time, and is based upon a range of Reddit threads, YouTube videos and social media posts from users who claim to have been shown adverts for products shortly after having conversations about them.

Facebook has spoken out in the past too, posting a statement to its press site in 2016 unequivocally denying it uses the microphone for any kind of listening in for advertising or News Feed story reasons.

“Facebook does not use your phone’s microphone to inform ads or to change what you see in News Feed,” the company said in statement in June 2016 – the last time conspiracy theories swelled.

“Some recent articles have suggested that we must be listening to people’s conversations in order to show them relevant ads. This is not true. We show ads based on people’s interests and other profile information – not what you’re talking out loud about.

“We only access your microphone if you have given our app permission and if you are actively using a specific feature that requires audio. This might include recording a video or using an optional feature we introduced two years ago to include music or other audio in your status updates.”

The additional feature the social network is referring to is a music recognition tool not available in the UK, where users can choose to turn on the mic when updating their status and have Facebook identify the track they’re listening to and include it as part of the status post.

Many within the tech industry think it is unlikely that Facebook would engage in such behaviour for a range of reasons – but most prominently because of the legal fallout if such a scheme was discovered, the various App Store rules it violates and the PR disaster it would also prompt.

One theory that has been put forward is users could be experiencing what’s known as the Baader-Meinhof phenomenon, also known as the frequency illusion.

The phenomenon is based on the idea that something you’ve heard about recently seems to appear more often in life that ever before.

The idea is that rather than something actually appearing more often, instead you’re simply noticing it more because you’ve engaged with the idea of it.

The crux of this argument is that we all scroll through millions of adverts on Facebook and elsewhere every year, the vast majority of which we pay no notice to, but should one appear that resonates with a recent conversation, it’s likely to catch the attention.

Facebook statement(Facebook)

It’s also worth remembering that Facebook and many other tech giants are able to use online activities and habits to target adverts at us – browsing history, Facebook interests and other factors for example.

High-powered and well-designed algorithms that shouldn’t be underestimated are at work here.

For now, it’s being marked as coincidence, but anyone who wants to turn off Facebook’s microphone access – which it asks for when you try to record video in the app – can do so from their phone settings.