Have you ever experienced that unsettling moment when, after casually chatting with friends – perhaps about the uncomfortable aftermath of a hefty roast dinner – you suddenly find yourself bombarded on the internet with ads for “anti-flatulence tablets” or “top tips for heartburn”? Or maybe you bought something relatively obscure online, like a tin of chopping board wood wax, only to be stalked for days by pop-ups offering the very same thing.

The algorithms immediately kick in, as if a command centre has sent out a signal: “Alert: Wood wax enthusiast detected in north London. Deploy all units. Hit them with everything we’ve got!” It sends a shudder down my spine to think that everything I am looking at online might be under surveillance. Not that I am a terrorist or serial killer or harbouring any dark secrets, honest.

I have as much morbid curiosity as the next person. My Google search history swings wildly from the utterly mundane (“terracotta window box with matching tray”) to the gleefully frivolous (“Lily Allen boob job”) to the grim depths of human depravity (“Josef Fritzl cellar”).

All fairly ordinary, I’d argue – but still, the contents of my meandering scatterbrain should be my own, not harvested to flog me more stuff I didn’t ask for.

At least for now the algorithms are easy to spot because they are not sophisticated enough to make sense of our data. That’s why they push items we’ve just bought, or make absurd suggestions based on a single search: “Hey, enjoyed Josef Fritzl’s cellar? You might love this basement dehumidifier.”

Even if I managed to kick the habit of feeding every passing whim into a search engine, it wouldn’t appease my creeping suspicion that our devices are eavesdropping on us. As it turns out my paranoia is entirely justified and shared among many others.

This week, a report revealed that sales of old-fashioned radios are on the rise in an unlikely comeback driven, it seems, by a growing distrust of smart technology, in particular, virtual assistants such as Amazon’s Alexa or Apple’s Siri.

Smart gadgets are, by design, always listening, apparently only springing to life the moment it hears its so-called “wake word”. Well, if any tech droids are listening in, I have a wake word for you… but I can’t print it here.