Some conspiracy theories are harder to dismiss out of hand — like the idea that Facebook is using your phone’s microphone to listen in on your conversations to serve you ads relevant to your interests. There are reports that claim if you use Facebook messenger, you are being recorded even when not on the phone.

While Facebook has been listening to your conversations since 2014, Kelli Burns, a communications professor at the University of South Florida, told The Independent in 2016 that Facebook could be listening in on users’ conversations all of the time to serve them with relevant advertising.

On its part, the social network admitted it uses peoples’ microphones, not for ad-targeting purposes but only as a way of seeing what they are listening to or watching and suggesting that they post about it. Facebook, which has a history of disrespecting users’ privacy, also revealed an easy way to revoke its access to your microphone. Here’s how to stop Facebook from listening to you on your phone.

So, is Facebook recording your conversations? The best evidence against the ‘conspiracy theory’ that Facebook is listening to your conversations is that Facebook strenuously denies it. But you will find it difficult to dismiss this conspiracy theory as totally crazy because there’s evidence that smartphone settings can be easily circumvented to allow surreptitious spying.

Well, if Facebook ads pop up with the same content as your conversations, it definitely feels like Facebook listened to your conversations. A video showing a couple’s successful attempt to get Facebook to show them cat food ads by talking constantly about cat food went viral last summer, and recently made the rounds on Reddit again.

Suspecting Facebook was listening in to his conversations, YouTube user Neville (who has no cats and who has never searched for cats or cat food) conducted a simple experiment.

“My wife and I took a random subject we had NEVER every talked about or searched online and talked about it while her iPhone was on in the background. Two days later, our Facebook advertising completely changed over to cat food for a few days.”

Creepy, yes, but is it true? The couple, obviously, says yes, and many Internet users agree.