There’s a dark irony to the scorn being poured on 5G conspiracy theorists right now. Which is that a lot of the ridicule is coming from those sections of society that have done more than their fair share to stoke up conspiratorial thinking in recent years.

Whether it is the unhinged idea that Russian bots made us vote for Brexit, or the obsession with Zionist power and its malign influence on British politics, conspiracy theories have become positively fashionable in the UK over the past five years. And such warped thinking has been promoted by the very people — Twitter leftists, supposedly sensible Remainers — who are now getting their rocks off by mocking the handful of 5G nutters.

The 5G conspiracy theory is mental. It’s a classic conspiracy theory. It features dastardly people with power — in this case evil tech companies — doing something awful to the rest of us: in this case exacerbating the spread of a novel new virus with their ‘5G contagion’.

As with all conspiracy theories there isn’t a sliver of evidence to back any of it up. And if you ask for evidence you’ll be told that you are one of the ‘sheeple’ who is so used to being drip-fed MSM lies that you have forgotten how to think for yourself.

Conspiracy theorists always see themselves as critical thinkers who have uncovered the truth, when of course they are the opposite: lazy, dogmatic ‘truthers’ impervious to evidence.

I got a taste of this in September 2006, on the fifth anniversary of 9/11, when the New Statesman sent me to interview David Shayler and Annie Machon in their Highgate home. Shayler and Machon were former MI5 agents who got into a spot of bother with officialdom after Shayler leaked sensitive documents to the Mail on Sunday in 1997. By 2006, they were full-on conspiracy theorists.

Their Highgate home doubled up as the hub of the British and Irish 9/11 Truth Campaign. It was in my interview with them that Shayler revealed that he had become a ‘no planer’. That is, someone who not only thinks that the American state orchestrated 9/11, but that there were no airplanes involved at all. They were holograms, Shayler explained to me.

Not a single bit of factual information — the fact that people saw and heard planes crash into the Twin Towers, the burning fuel, the vast data logs about the flights and the passengers, etc — could cut through his theory.

Since then, I’ve had a deep dislike of conspiratorial thinking. It is, in my view, very bad for public life. It promotes paranoia; it replaces the noble enterprise of scepticism with the tawdry hunt for the secret networks of powerful people who are apparently puppeteering our lives; and it cultivates passivity, through convincing people that there is little they can do about the dark forces who control the world.

For that reason, conspiracy theories are bad for democracy, too, in that they reduce citizens from engaged individuals who can use their beliefs and their votes to try to change society to hapless creatures moved around on a chessboard board by super-powerful bankers, Zionists, tech overlords, or whatever.

Conspiracy theories often nurture anti-Jewish racism, too. It seems clear to me that the Corbynista left’s drift into anti-Semitic thinking in recent years was a product of the modern left’s abandonment of rational analysis of the relations of capitalist society and their embrace instead of the infantile notion that gangs of bankers and evil landlords are treading us all underfoot. The more anti-intellectual and paranoid the left became, the more susceptible it became to the foul old Socialism of Fools.

This brings us to the 5G idiocy. There’s a really important point to be made about this conspiracy theory: it didn’t come out of the blue. No, the 5G madness emerged in a society in which even supposed intellectuals and political activists have been drawn into the conspiratorial universe.

Indeed, at the exact time as some excitable Scousers and Brummies have attacked 5G masts, we have seen conspiracy theories coming from other sections of society, too. Yesterday we had Chris Williamson, one-time darling of the Corbynista left, saying the reason the Labour party now accepts it had an anti-Semitism problem is because some of its top people have ‘internalised the myths forged by the State of Israel and its UK lobby’. A classic anti-Semitic conspiracy theory.

Then there are the conspiracy theories pushed by hardcore Remainers like Carole Cadwalladr, who believes vast secret networks of rich people and Russians were behind the vote for Brexit. Cadwalladr even thinks there is a ‘secret club of people who rule Britain’. She and others in the Hard Remain camp have made paranoid thinking thoroughly mainstream in chattering-class circles.

And let’s not forget that respectable people were at the forefront of other deranged theories, from the ‘MMR causes autism’ nonsense, which was enthusiastically embraced by some liberal columnists, to the myth of Satanic ritual abuse, which was promoted by social workers and feminists.

So, yes, make fun of the 5G conspiracy theorists. They deserve it. But at the same time let us please challenge the broader politics of paranoia that the middle classes bear a great deal of responsibility for. For that is the political dirt in which mad theories fester and grow.