Many of us can remember the shock. Naked ladies! In a magazine! A magazine your best friend found in a pile under her brother’s bed! The ladies wore high heels. They were smiling. They were having a lovely time. But, still, to see those naked ladies, as you giggled with your friend, was a shock.

Porn has moved on a bit since then. Now, when children stumble across it, what they find is – well, let’s not go there while you’re eating your breakfast or lunch. And they do stumble across it, on their phones. According to a report commissioned by the NSPCC last year, about half of 11- to 16-year-olds have seen explicit sexual material online. They were, the report said, more likely to find it accidentally than to seek it out.

The consequences are pretty awful: children trying to copy what they have seen; children not understanding the concept of consent; children thinking that violence and screaming are a normal part of sex. Expert witnesses told the women and equalities committee last year that girls are now wearing shorts under their skirts, in an attempt to survive the “normalised culture of sexual harassment in schools”. Children, in other words, are being stripped of their childhoods.

So it has to be good news that from April next year people in the UK will have to prove that they’re 18 before being allowed to access porn sites. “The UK,” said digital minister Matt Hancock in a statement to the Commons, “will have the most robust internet child protection measures of any country in the world.” And this won’t just be a box you tick. There will, apparently, be rules. And companies breaking those rules may be blocked.

Oh, and users may be asked to give credit card details, and perhaps even be charged a small fee. A fee that might appear on a bank statement that might, for example, be seen by your wife. These things will be for a regulator to decide, but the thing is this: your porn habit will now have what tech companies like to call a bigger “footprint”, and one that might well make some users think twice.

Goodness only knows what Liberty will say. Or, of course, Julian Assange. Is this the end of freedom as we know it? Is it Tories trying to annex parts of the left’s nanny state? Is our government trying to “nudge” its adult citizens into sexual behaviour and viewing habits that wouldn’t bring “a little tear” to a vicar’s daughter’s face?

The answer to all of those questions is: probably not, not least since a government that can’t control a few middle-aged men in its cabinet is unlikely to get very far with 51 million adults. It’s children they were trying to protect, and the only way to protect those children is to make all users of online porn leap through a few hoops. But if those hoops prove a bit of a deterrent to adult users of porn, then some of us might want to slap Hancock on the back. In a gentle, consensual way, of course.

Porn warps. I’m sorry if you love it, and find it spices up your sex life, but the evidence is there. Last year, Pornhub had 23bn visits. Which would be fine if all those videos were of men and women having a lovely time. They are not. According to the anti-pornography website Fight the New Drug, some of the suggested searches on popular porn sites include terms such as “crying in pain”, “extreme brutal gangbang” and “sleep assault”. And data published by Pornhub itself reveals that “step mom” and “teen” are among that site’s most popular search terms.

It’s possible, of course, that people watch this stuff and remain loving partners and pillars of society. It’s more likely that they don’t. I’ve interviewed a number of men whose porn addiction, and sexting habits, have lost them their marriage, their jobs and their homes. These are the extremes, of course, but there’s not much doubt that porn is changing our culture. Robert Weiss, one of the world’s leading experts on digital sexual behaviour, told me that we’re “evolving to be a less intimate culture”. He thinks machines will soon supply a lot of our sexual needs. He didn’t say whether or not they would be programmed to scream.

The internet has already changed so much of our culture. We rage. We shriek. We hate. We do this in the name of “free speech”. We buy things with a click. We swipe for sex. We want instant everything, all the time. And we want it all to be free.

When Tim Berners-Lee imagined “an open platform that would allow everyone, everywhere, to share information, access opportunities, and collaborate across geographic and cultural boundaries”, he probably didn’t dream of a wild west that would do us so much harm. We have laws to protect us from harm. Yes, those laws curb our freedom. And I can’t wait for the day when we’re all a little bit less free.

• This article was amended on 24 July 2017 to clarify a reference to popular search terms on pornography websites.