This evening, while you settle down to watch Death In Paradise or Birds Of A Feather, the disturbing reality is that your television set may also be watching and listening to you.

If you own a ‘smart TV’ from South Korean tech giant Samsung, every word you say can be captured by the device and beamed over the internet to Samsung and to any other companies with whom it chooses to share your data.

This ability for the TV to earwig your conversations on the sofa is part of the set’s voice command feature, which enables viewers to tell the TV to change channels rather than use a remote.

Such a feature is typical of many smart TVs, which are to the humble old cathode ray TV set what a jet aircraft is to a propeller plane.

Crucially, smart television sets connect to the internet, from where they can download programmes and films from services such as Netflix or BBC iPlayer. And increasingly, experts are realising that if the internet can be used to bring information into your TV, it can also be used to take it out.

Smart TVs also have a whole range of advanced features, of which voice recognition is one.

There is no doubt that many viewers find voice recognition a welcome addition, but its darker side was revealed this week when a hawk-eyed U.S. journalist found the following sentence in Samsung’s surely misnamed ‘privacy’ policy.

‘Please be aware that if your spoken words include personal or other sensitive information, that information will be among the data captured and transmitted to a third party through your use of voice recognition.’

The TV itself is programmed to understand certain phrases, such as ‘turn on’, but it can also record everything else that is said in the room.

The idea that your most private conversations could be shared with anyone whom the unaccountable Samsung sees fit is highly disturbing to say the least.

And it’s not just television sets. It emerged yesterday that millions of Britons are being spied on by Microsoft’s voice-activated Xbox games consoles, which can listen in to everything around them.

In its privacy policy, Microsoft states that it is ‘only interested in your voice commands to Xbox, which we capture along with any ambient background noise. If you give Microsoft permission, we record commands whether you are online or offline’.

The company says it stores this data and, under its privacy policy, states that it can share it with ‘affiliates and vendors’.

However, despite Microsoft’s assurances that the data is safe, one has only to look at how Xbox’s Live Platform servers were brought down by hackers on Christmas Day to realise that our data is far from secure.

These spies in our living rooms are chillingly comparable to a passage in the novel Nineteen Eighty-Four, in which every home in George Orwell’s terrifying vision of a constantly monitored future is equipped with an all-seeing ‘telescreen’.

‘There was, of course, no way of knowing whether you were being watched at any given moment,’ wrote Orwell in the book that was published in 1949.

And, just like those fictional ‘telescreens’, many smart TV sets today don’t just have ears, but they also have eyes, in the form of cameras used for facial recognition, which are designed to allow only specific people to watch the set.

Facial recognition is a technology that seems to improve constantly: for example, the software can recognise individuals by comparing the lengths between specific points on their faces — such as the distances between our ears, or between our eyes and mouth.

In its privacy policy, Samsung states that images of your face are not sent over the internet, but why should we take such claims on trust? Likewise, even if we turn off the voice recognition function, how can we be sure they are not recording what we say anyway.

Just look at the recent case of a smart TV sold by South Korean tech giant LG, which continued to monitor users’ viewing habits, even when they had disabled the relevant feature.

LG wanted the data to assess how people used their TVs, but you don’t have to be much of cynic to know that such data can be sold for a fortune to advertisers.

The truth is there are hundreds of ways in which we consumers have permitted multinationals to invade our homes with devices that can record every word we say and every movement we make — even every toss and turn when we are asleep.

We are being spied on and stalked in this way because our private lives are seen as nothing more than rich sources of data that can be sucked dry by vampiric corporations desperate to empty our wallets.

‘I don’t think people are aware of quite what they have allowed to happen,’ says Bernard Marr, author of an exposé of this high-tech spying called Big Data. Mr Marr advises companies and governments on how to handle all their information, and he adds: ‘It’s no good saying “I have nothing to hide”, because what can be done to any of us with this information is very dangerous.’

You only have to look around your home to realise this is no exaggeration. Perhaps, like me, you have recently bought yourself a little device called an Amazon Fire TV for £79.

It’s a small box that connects to your television set and the internet, and enables you to download TV shows and films directly from Amazon and view them almost immediately. One of its features is voice recognition. The wearisome webpage ‘Amazon Fire TV terms of use’ says that any voice recordings ‘may be stored on servers outside the country in which you live’, and cagily admits that third parties ‘have access to personal information needed to perform their functions’.

That sounds ominous — it seems to mean that the tax-shy company is entitled to share any recordings it makes of me with whoever it chooses.

What if they eavesdrop on me telling my wife that we really need a new vacuum cleaner or that I’d love to go to Italy this summer?

That information could be sent on to other companies who might then find ways to bombard me digitally, via email or the internet, with intrusive adverts for carpet cleaners or trips to Rome.

For example, if you use Google’s Gmail service, then you’ve long since signed away any privacy in your life.

Have you ever noticed how the adverts that appear alongside emails seem oddly applicable to you? Of course, that is no coincidence — Google reads every email you send and receive, and then works out which goods and services you might want to buy.

Try it — send some emails about moving house and within minutes, the adverts will be all about mortgages and estate agents.

And then there is the so-called ‘Internet of Everything’, which refers to the increasing number of household devices that are hooked up to the internet.

For example, with the humble heating thermostat, many energy companies are offering customers ‘smart meters’ that enable us to control our boilers over the internet using our smartphones.

This cleverly allows us to put on the heating remotely as we head home from work, for example — but it also means that the companies will be able to know when we are at home or out . . . and when we go away on holiday.

Even our physical activities are not safe from the relentless march of digitalisation.

An American firm called Jawbone sells an electronic wristband called an ‘Up’, which monitors how much we exercise and our sleep patterns. All this data is shared with the firm, supposedly for our benefit.

Naturally, all these companies claim that they are tracking our behaviour simply to make the services more personal to us.

That may well be true, but again, how can we trust them to keep our personal details secure. For governments, even those of the most supposedly liberal hue, look at all this snooping technology developed by private firms with beady eyes.

If our TVs can listen to us, then you can bet that somewhere in the Home Office, a grey-suited civil servant is drawing up plans to allow the police to have access to our smart TVs, all in the name of fighting terrorism.

It is tempting to speculate what George Orwell would have made of all this.

In his dystopia, the people have no choice but to allow Big Brother to watch them, but in our unfortunate real world, we have willingly allowed lots of Little Brothers into our lives.

Together, they have combined to produce something even bigger and more sinister than Orwell could ever have imagined.

We should stop calling these devices ‘smart’ and call them what they really are — spies.