The internet, like DNA, is a mechanism for passing on information. Like DNA, large parts of the internet have no outwardly-obvious function. Perhaps there are scientists earnestly scrutinising cat videos trying to work out why they are there (perhaps junk DNA encodes cat videos).

In each case, the really dangerous part isn’t the junk, it’s the corruption of the important information. The nature of lying online has changed the way in which untruths have affected public debate. It’s well past time that we took stock.

Lying wasn’t invented on the internet. In the past, however, the ability to tell a narrative-changing lie was severely restricted. In the early part of the twentieth century, mass communication was in the hands of those who owned newspapers. The barriers to entry were high and newspaper audiences were large. The influence of the owners was enormous. Not for nothing were they called press barons.

We should have no false nostalgia for the age of the fourth estate. At least one British election was hugely influenced by press lies – the Zinoviev letter remains notorious. Journalism was seen as a byword for venality and unfairness. Moreover, much information that was of huge public interest was kept from the masses because the political classes could effectively control the small group responsible for public information. Edward VIII’s assignations with Wallis Simpson were not publicly known in Britain for many months (though covered in detail in other countries).

The internet destroyed the barriers to setting up information provision. Suddenly anyone with a computer and an internet connection, a readable writing style and with some information to offer could open for business.

Initially, this seemed like an unqualified positive. Want to know about opposition politics in Hong Kong? Developments in bee-keeping? The technical changes to Formula 1 constructor requirements? The internet could fulfil your needs more quickly and more comprehensively than any newspaper or magazine could ever hope to.

Some of this has been truly transformative. There are now more than 5.5 million articles on the English version of Wikipedia, a single repository of knowledge unlike anything ever previously seen in any previous encyclopaedia.

The worm in the apple took some time to break cover. It had long since been appreciated that online information that had not been peer-reviewed might be wrong or misleading through inadvertence or might present a highly tendentious view of the truth from the writer’s personal viewpoint. Readers were well-aware that some might present deliberate lies defensively. All of these problems were familiar from past experience with the media.

The idea of someone presenting deliberately untrue information as an active policy was something new. It had not previously been practical because of the gatekeepers at the top of the media who could bar access to the public. With that control gone, the way was open for anyone who wanted to launch a campaign of misinformation.

It started relatively innocently, with mischief-makers on Wikipedia tinkering for kicks. Some saw the business opportunity in heart-warming clickbait, whether or not the inspirational story was in fact true (see Daisy the Dog for more details).

Then the political implications began to sink in. “In wartime, truth is so precious that she should always be attended by a bodyguard of lies”, Winston Churchill advised. It is apparent that many fighting wars online feel exactly that way.

Why are internet lies so successful? First, people want to believe stories that are congenial to their worldview. Corbynites, Leavers and those on the Trump train are obvious examples of this phenomenon, but those on the opposing side of each of these groups can be just as guilty of wishful thinking. Why scrutinise carefully a story that confirms your prejudices?

Secondly, debunking a lie takes time as the facts are established. Previously, journalists would have done the job. But the media’s response to the pressure on costs that the internet has driven was to cut those costs. Among the most expensive costs were the salaries of the journalists who did the fact-finding. So the people who used to do this just aren’t doing this job any more.

I’ve already quoted Winston Churchill so I’d better quote Oscar Wilde as well: “The truth is rarely pure and never simple”. Truth is fractal – the more closely you look at it, the more qualifications you need to put on the assertion. This leaves plenty of scope for argument and the original claim can get lost in an argument over an essentially trivial point. Moreover, the truth is usually quite humdrum. But (this is my thirdly) a lie is subject to no such need for restraint. It needs no nuance and can be as exciting as its creator wishes it to be. And who doesn’t like lurid excitement?

Fourthly, it’s human to want to lead the pack. Once CNN exhorted us to “Be the first to know”. Now we want to be the first to tell. Why check when you can be claiming kudos points?

So, in a news version of Gresham’s Law, bad information drives out good. We hoard the quality stuff and pass on the rubbish.

What can we do to combat this? In short, be sceptical. If you’re told something eyebrow-raising, look for a primary source to back it up. Try to get context.

Be especially sceptical of information that produces a strong emotional response from you. Ask yourself who wants to produce that response.

Don’t be part of the problem. If you are retweeting without first checking your information, you are a vector.

At the moment, fake news is achieving its proponents’ ends spectacularly. In the long run, it will subside as the internet public become more wary of their source material. For now, trust no one.

Alastair Meeks