Jon Ronson’s latest book, So You’ve Been Publicly Shamed, looks at how some people’s lives have been ruined by the reaction to an ill-judged social-media confession or a clumsy tweet. A new chapter for the paperback edition reports on how he too became a victim of aggressive censure for suggesting that the “shaming” of people like Rachel Dolezal (the white civil-rights campaigner who identified herself as black) was a form of vicious mob rule.

The phrase that kept cropping up in my mind as I read your book was the way a News of the World journalist described his job: “This is what we do: we go out and destroy other people’s lives.” It used to be the most out-of-control tabloid journalists doing that – is it now anonymous social‑media trolls?

I’ve noticed all year this weird psychological thing going on that people who love finding faults in others for abuses of power react with a fury when it is pointed out that they are abusing the power of social media themselves. Time and again on Twitter we act like the thing we purport to hate.

At least with conventional media there is some protection from shaming in the law. Max Mosley got his day in court…

Yes. But there is a toxic relationship between mainstream media and social media, I think. To begin with old media just ignored Twitter; then it tried to emasculate it by doing “the 50 best tweeters” pieces, trying to control it. I remember feeling disappointed about that because the whole point of Twitter was that it was egalitarian, someone with a hundred Twitter followers can be just as entertaining as someone with a hundred thousand. And then what happened was that mainstream media began to bow to Twitter’s agenda setting.

Obviously you were quite seduced by it to start with, and not above a bit of naming and shaming yourself. Didn’t alarm bells go off?

Not to start with. I thought it offered a chance to do things better, to right certain wrongs. But what quickly started to happen was this kind of mob mentality.

You talk in the book about being bullied as a teenager. I guess that is one of the reasons you became a journalist, to stand up for people without power and to hold to account or ridicule those who abuse it. Is that what also drew you to this subject?

Yes. When I saw what happened to Justine Sacco [who saw her life ruined after she tweeted a “joke” in poor taste about the racial politics of Aids in Africa] I definitely responded to that in part because of the experience of being bullied at school. That kind of self-righteous bullying that was happening to Justine. Bullying in the name of compassion.

It seems to me that the harshness of the tone of social media is having a direct effect on politics and public life, increasing polarities?

I really liked Barbara Ellen’s line in the Observer: “When did being ‘moderate’ become an insult?” I agree things have become more extreme. I think it is in part because social media is a stage for constant artificial high drama. Everyone is either a magnificent hero or a sickening villain. That is the toxic gift that Twitter has given: grey areas have become unfashionable.

Germaine Greer appeared at the University of Cardiff last month despite a campaign to prevent her speaking. Photograph: Michael Hall

Because nuance and empathy – and fact-checking – become seen as a sign of weakness?

Yes, in the first talk I gave about the book I compared Twitter to the Stasi and the audience kind of loudly tutted and I thought: “The only reason you are tutting is that you haven’t thought this through.” We have created this surveillance society where we are always looking for clues to our neighbours’ secret inner evil…

The obvious argument against the Stasi comparison is that people don’t have to participate, though increasingly I suppose young people in particular find it hard not to…

Yes. And of course the Stasi were stealing people’s secrets, where the people I am talking about give theirs up voluntarily. But then Justine Sacco had 170 Twitter followers she sent her joke to. She could not have expected that by the time she got off her plane that tweet would be the number one trending story around the world. I think people can reasonably assume that when they send a message to a hundred followers nothing terribly bad is going to happen. I don’t think the analogy is nuts.

Has the reaction to the book been different in America?

The book became very talked about in America. I have felt like I’ve spent all year explaining it. The problem was that almost no one who attacked the book had read it. It was seen as an attack on social justice.

Do you find yourself self-censoring these days?

I do totally online. Not in my writing. I’m hardly every attacked for stuff I write in a book. I think everyone with a load of Twitter followers now feels like they are in a minefield, like a bomb disposal expert working out which wire to cut.

You used to be a 20-tweet-a-day man. Do you miss that?

I do miss the old days. Sharing jokes with strangers really helped my mental health. To begin with people would admit little things about themselves and other people would say: “Oh my God, I’m exactly the same.” There was this shared destigmatising thing. That is at risk of going. It’s now often about hunting for people’s transgressions and shameful secrets.

This censorious attitude filters out into the real world, it seems. We have the absurd situation where, say, Germaine Greer can’t talk at universities because of social-media pressure…

I went to college in the 80s in London. We were all social-justice people but there was always one person who was way more social justice than everyone else. It can seem like that fucker from the 80s is now in charge, and no one is allowed to say anything. I mean I still consider myself a politically correct person, and we don’t want to go back to racism and sexism and homophobia, of course. But it has got to the point where a lot of comedians over here [Ronson now lives in New York] won’t play colleges in case someone puts something online out of context.

As you argue in the book, there are financial imperatives for Twitter and Google and Facebook and the rest to maintain this attitude…

Yes. The corporations don’t want blandness or complexity. They want spikes of outrage. Journalism was always about speaking truth to power. But increasingly people are wary of trying to speak truth to social media I think.

The paperback edition of So You’ve Been Publicly Shamed is published on 31 December (Picador £8.99). Click here to preorder it for £7.19. The Jon Ronson Mysteries is at Leicester Square theatre, London, 26-30 January 2016