Over the past fortnight, five prestigious institutions in the U.K. have banned Robin Thicke's saucy R&B ditty Blurred Lines from playing anywhere on their premises, on the basis that its overly sexual lyrics might encourage bad behaviour in men.

Which institutions, I hear you ask? Stuffy churches, perhaps, aghast that a song would promote casual sex? Islamic groups, maybe, believing that lines like "I know you want it" are not suitable for young ears, especially female ones? Or maybe it was killjoy police forces, not exactly renowned for their ability to chill out, which forbade the playing of Thicke's tune?

Nope, it was student unions. Five student representative bodies—at the Universities of Edinburgh, West Scotland, Leeds, Derby and Kingston—have banned Blurred Lines in all the premises in which they have dominion, including student bars and dancehalls, on the basis that it "undermines and degrades women" and "promotes an unhealthy attitude toward sex and consent".

Once upon a time, students' political leaders kicked against authoritarianism; now they enforce it.

In the space of a generation, they've gone from demanding the right of young adults on campus to listen to, dance to, read and watch what they want, to placing a paternalistic hand over students' ears and eyes lest they hear something a bit raunchy.

Blurred Lines, a massive global hit sung by Thicke with Pharrell Williams and the rapper T.I., has been the subject of controversy since it was released in March. The modern breed of sexless, censorious feminist has been particularly vocal in slamming both the song and its accompanying video, which features the three singers, fully clothed, cavorting with some very attractive models wearing only flesh-colored thongs. Blurred Lines is "creepy" and "a bit rapey," says one observer.

Now, British student unions have taken this shrill reaction to what is just a pretty good and perfectly harmless pop song to its logical conclusion. The student union at Edinburgh kicked things off on 12 September by banning Blurred Lines from every student building. It did this as part of its policy to "End Rape Culture and Lad Banter" on campus.

It's hard to work out what is most shocking about the Edinburgh union's ban-happy antics: the fact that it thinks nothing of behaving like a nun at a convent-school disco and switching off any song that mentions the sex act, or the fact that it has an actual policy to "end lad banter"—that is, to prevent young men from speaking in a certain gruff, licentious fashion. Quite when student leaders switched from fighting for students to fighting against them, and against their apparently demonic thought and speech patterns, is a mystery.

The Edinburgh union said Blurred Lines "trivializes rape," and in doing so it contributes to "a culturally permissible attitude to rape." Really? Are the minds of male students so malleable, so putty-like, that a single encounter with lyrics like "You're an animal, baby, it's in your nature" and "Let me liberate you" might be enough to push them towards committing rape?

Behind the Edinburgh union's pseudo-radical, feminism-justified banning of Blurred Lines there lurks the old, highly discredited spectre of media effects theory—the idea that media images and words pollute people's minds and make them behave in all sorts of sordid and even criminal ways. Just as Britain's stuffy old censors of the pre-1960s period refused to let the public read D.H. Lawrence's Lady Chatterley's Lover on the basis that it might make them immoral and depraved, so today's youthful, rosy-cheeked student censors refuse to allow their charges to hear Blurred Lines on the basis that it could turn them bestial.

The instinct behind the Edinburgh union's banning of Blurred Lines is the same one that has motored every act of censorship in history: a paternalistic urge to keep the little people's base motives in check by protecting them from sexy, blasphemous, or shocking imagery.

Other student unions have followed Edinburgh's authoritarian lead. The union at Leeds University banned Blurred Lines on the basis that it "degrades women." Kingston University in London has banned it due to "the disrespectful nature of the lyrics." If universities only play songs with respectful lyrics, what will happen to gangsta rap, the Sex Pistols, the Velvet Underground, death metal, or any other musical genre that broaches the old chestnuts of sex, drugs and rock'n'roll?

Student leaders' intolerant war on Blurred Lines fits a depressing pattern in modern British university life. In the UK, as in other parts of the Western world, students have become extraordinarily censorious in recent years, seeking to obliterate from campuses any song, book, newspaper or person that has the temerity to offend their sensibilities.

Various British student unions have banned Eminem's songs (they're homophobic and misogynistic, apparently); the tabloid newspaper, The Sun (because it has a naked woman on Page 3, and men and women over the age of 18 can't possibly be exposed to tits); and right-wing or Zionist speakers—numerous unions have "No Platform" policies, which means they forbid inviting far-right or Zionist spokespeople to take part in debates on campus.

We seem to have nurtured a spectacularly narcissistic generation, many of whom seem truly to believe that it is perfectly natural and reasonable to demand the squishing of anything that offends them. This is the grisly end product of the self-esteem culture: having educated young people to believe that their self-esteem is sacrosanct, and that anything which dents it is evil, we cannot now be surprised that they believe they have the right to erect a moral, censorship-powered forcefield around themselves and their peers in order to ward off any idea or image or song that makes them feel bad.

Universities, or at least some of them, were once hotbeds of radicalism, sites of feverish and excitable political debate in which any idea was permissible, especially if it railed against adult society. Not now. Today, universities in Britain and elsewhere have become breeding grounds for nanny staters and nudgers, training courses for the blue pen-wielding authoritarians of the future. That's the most worrying thing about the student reps currently bashing Blurred Lines—one day, these joyless, casually censorious, fun-allergic misanthropes will be running Britain.