On May 25th, amateur musician Alison Chabloz was convicted of criminal offences in relation to three songs. Her conviction followed a private prosecution by Campaign Against Antisemitism, which was taken over by the CPS.

Ms Chabloz’s lyrics not only suggested that the Holocaust was ‘a bunch of lies’ but attempted to stir up age-old resentments with a gamut of antisemitic clichés, informing her listeners that Jews – or, to use her own phrase, ‘eternal wandering liars’ – control the media and are ‘bleeding you dry’.

Not so long ago, a private performance before an audience of neo-Nazis would have been the only possible outlet for a hate-monger like Ms Chabloz. Certainly, no reputable broadcaster would have wanted anything to do with her. But this is the 21st century, so to reach a potentially unlimited audience, all she had to do was to upload recordings of herself to YouTube and share them on Facebook and Twitter.

Writing in the Jewish Chronicle last month, Times columnist Oliver Kamm argues that, just as ‘racists and Holocaust deniers don’t have access to the pages of The Times or to the BBC’s airwaves’, they should have no right to disseminate their views through social media platforms, as those too ‘are publishers and not just public forums.’ We agree with him thus far.

But he goes on to suggest that Ms Chabloz and her ilk could somehow be prevented from using social media without prosecution, and in this, he is wrong.

In an ideal world, YouTube would not have published Ms Chabloz’s songs in the first place. But its general policy is to consider blocking or removing offensive content only after publishing it, and only in response to complaints.

And blocked or deleted YouTube content has a habit of finding its way back to the site on different channels and under other names, leaving concerned citizens to play Whac-A-Mole with the ‘report’ button.

So, in the real world, the only way to prevent social media platforms from being used for such vile ends is through legal action and the threat of it: and not only against individuals like Ms Chabloz, but also eventually against the platforms themselves, if they cannot put their houses in order.

Under section 127 of the Communications Act 2003, a person is guilty of an offence if he sends by means of an electronic communications network a message that is grossly offensive. In the absence of Holocaust denial laws, this was the only possible statutory provision that Ms Chabloz could have been charged under.

And in the absence of more socially responsible policies on the part of YouTube, Facebook, and Twitter, a charge under that act is the only realistic way of putting a brake on the spread of hate.

Many people, including Mr Kamm, argue that the public dissemination of Holocaust denial material, despite its being "grossly offensive," should be immune from criminal prosecution on the grounds that it is, or should be, protected by the "right to offend." This argument is based on the claim that the "right to offend" is a "free speech right" and that the criminalisation of Holocaust denial material infringes that right and poses a danger that other material that offends religious sensibilities, or indeed any other offensive material, will be censored.

This is the so-called "slippery slope" argument. 

It is a fallacious argument because every case turns on its own unique facts and circumstances.

Just because Ms Chabloz's songs were found to be "grossly offensive" does not mean that other material that offends will be found to be "grossly offensive" or even that every other instance of Holocaust denial will be found to be "grossly offensive." In any event, a decision by the Magistrates Court, which is a trial court, does not set a precedent.

So, practically speaking, the slippery slope argument is without foundation.

The right to free speech in a democratic society must be weighed and balanced against other rights, such as the right to be free from religious and racial hatred. Indeed, it is particularly important that the publication of Holocaust denial material should not be tolerated.

This is because Holocaust denial goes beyond mere "offence".

Holocaust deniers insinuate that the Jews faked their own genocide for self-serving ends, for example to extract money from Germany or to justify the "oppression of the Palestinians". Their arguments rely upon and promote the idea that the world is controlled by an international Jewish conspiracy.

And there is also evidence that Holocaust denial can incite violence against Jews. It is for these reasons that Holocaust denial is a crime in 16 European countries as well as Israel.

The argument that criminalising Holocaust denial is incompatible with the European Convention on Human Rights and the Universal Declaration of Human Rights has been rejected by the Institutions of the Council of Europe, the European Commission of Human Rights, and by the United Nations Human Rights Committee.

In other words, there is no free speech right to deny the Holocaust.

It is naïve to suggest that Holocaust denial should be allowed so that it can be openly debated. Holocaust denial has persisted despite the fact that the Holocaust is one of the best documented genocides in history, with huge volumes of evidence documenting virtually every aspect of it. Holocaust deniers are malicious propagandists who cannot be reasoned with or engaged; they have to be silenced.

Dr Daniel Allington is Lecturer in Digital Media at the University of Leicester and Head of Online Monitoring for the Campaign Against Antisemitism

Dr Lesley Klaff is Senior Lecturer in Law  at the Helena Kennedy Centre for International Justice, Sheffield Hallam University, and Editor-in-Chief, Journal of Contemporary Antisemitism