This year, the internet went insane with the theory that our phones are listening to us. F.B.I. spy memes went viral and conspiracy threads clogged Twitter – everything we type/say into our phones is being read and heard by Mark Zuckerberg, the government and, if some Reddit threads are to be believed, aliens too.

It’s certainly happened to many of us. Phone nearby, you have a conversation with a friend about food supplements, for example. Soon after, your Facebook and Instagram feeds are filled with ads for Holland and Barrett.

Or, you could message a friend via Facebook and make plans to meet at a certain venue. Suddenly that exact place appears on your feed as a suggested page to follow. With so many people reporting instances like this, it’s easy to assume that to some degree, we are being monitored.

Facebook issued a statement in 2016, assuring users that their conversations were not being recorded or listened to:

“Facebook does not use your phone’s microphone to inform ads or to change what you see in News Feed. 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.”

Facebook may deny using smartphone microphones to monitor users, but what about in-app conversations via WhatsApp and Instagram? As WhatsApp and Instagram are owned by Facebook, user information may be shared between the three applications. It’s highly plausible that an algorithm exists to scan user conversations, find key-words and target ads towards the user.

With this theory in mind, we conducted our own experiment to test whether WhatsApp and Instagram direct messages are being monitored in order to reveal user preferences and personalise advertisements.

Using two iPhones, we restored them to factory settings and wiped them clean to ensure no history of data is left on the phone to determine the outcome. We also inserted two Eir sim-cards with new, unused numbers.

Following that, we created two separate Facebook accounts depicting two middle-aged women, named Anna Boyle and Margaret Freeman. We also created two Whatsapp accounts registered to our new numbers, and two Instagram accounts under the same names.

We then started conversations between both Whatsapp and Instagram accounts, including a number of pre-picked keywords: Yankee candles, Brylcreem, ice hockey, Camile Thai, Tupperware and Johnson’s talcum powder. Repeating these keywords, we continued the conversations everyday at the same time for two weeks.

Conclusion: It can be accepted that WhatsApp seems to be fully encrypted, as none of our chosen keywords appeared as ads on Facebook. However, two of the keywords we mentioned via our Instagram chat appeared as ads.

While of course we can’t declare for 100% fact that Facebook is monitoring Instagram’s messaging feature, our experiment results definitely lean towards a possible algorithm being in place. Without sounding too ‘big-brotherish’, it’s safe to say that your phone definitely knows a whole lot about you.