As a new MP in 2015 – and a new user of social media – it took me some time to adapt.

I thought at first when people wrote to me on Twitter the rules of normal social intercourse applied. I might disagree with someone. But if I responded, courteously, we could agree to disagree amicably.

I was quickly disabused as online trolls screamed abuse.

Why are these people so angry?

The Commons Culture & Media Committee on which I sit has undertaken detailed inquiries into the areas of disinformation, misinformation, and the impact of online filter bubbles which show people content based on their existing viewer biases.

Now for some people that can be innocent enough. But for others, the filter bubbles are far from benign. Facebook itself warned its staff that its algorithms “exploit the human brain’s attraction towards divisiveness”.

In other words if you watch one conspiracy video the chances are you’ll immediately get sent another conspiracy video reinforcing your paranoia.

The result is to drive some users into a frenzy. This is why people blow up 5G masts convinced they’re the cause of Covid.

But it’s not just the ignorant and under-privileged who fall prey. Even graduates of the world’s most elite universities can become victims.

Donald Trump thought injecting bleach could cure Covid. And Boris Johnson wondered whether blowing a hairdryer up his nostrils might save him from the pandemic.

Filter bubbles pose an enormous threat to our democracy as well as our health. We know how heavily engaged Vladimir Putin was in encouraging people to vote for Brexit by spreading disinformation online.

And in the United States – swept away in a tsunami of ignorance, prejudice, and shared disinformation – those who stormed the Capitol believed the victor had lost and the loser had won.

So what responsibility should MPs take? We should certainly have dealt much sooner with cynical and unscrupulous social media companies driven only by profits and scared only by threats to those profits.

Politicians, I believe, are directly responsible for the way disinformation is spread which they initiate.

Take, for instance, the much-ridiculed Conservative Party claims that the UK Government had prevented incoming bans on meat, single car usage, and a ‘new rule’ that we must all have seven household bins.

The claims were ludicrous – none of these bans and rules were real. But does disinformation like this matter?

I think it does. Knowingly spreading disinformation helps only those who would undermine our democratic institutions.

It erodes voters’ overall trust. Some call it post-truth politics: conditioning voters to believe no one and nothing, to treat trusted sources with suspicion – to think there’s no difference between Channel 4 News and GB News.

My Committee found repeated, successful attempts by bad faith actors to insert their talking points into our democratic discourse online. But social media companies have shown little interest in tackling them. They were disdainful witnesses when we summoned them.

All of us hope the new Online Safety Act will help.

But alas the evidence suggests that our woefully inept regulator Ofcom will continue to be found wanting.