In this article Simon Jenkins is in no doubt about the destructive, corrosive nature of online abuse and the need to stamp it out. But rather than jumping to instant conclusions he stresses that we do not know who is posting the abuse or even if “they are orchestrated or just a bunch of thugs”. His call for deleting from social media anything that “the reader, or at least some moderator, cannot identify” should be seriously considered.

There is something strange in Labour’s antisemitism row. The abuse described by Labour MPs in the Commons on Tuesday was awful. Attacks on anyone on grounds of their race or religion are indefensible. Jeremy Corbyn’s support for certain lobbyists (and murals) indicates a serious lack of judgment, but being anti-Israel does not make him antisemitic, any more than my view of some Arab countries makes me anti-Muslim.

What distinguishes this row is the anonymity of the real “antisemites”. We do not know who or where they are, how many there are, or whether they are orchestrated or just a bunch of thugs. Their poison enjoys the immunity of the great god, social media.

I have known the Labour party all my life, and somewhere still have my student membership card as a souvenir. The party never seemed to me “institutionally antisemitic”, any more than does the Conservative party. A genuine strength of British politics is that parties across the spectrum embrace diverse groups. MPs are regularly heckled at meetings – and those who cross a certain line are vulnerable to the criminal law. But Labour’s so-called enemy within appears largely confined to social media and guilt by association. The Tory MP Andrew Percy accuses Corbyn of being “in racist antisemitic Facebook groups”. According to the New Statesman another, Robert Halfon, refers to “Facebook groups containing antisemitic tropes that had Labour high-ups, including Corbyn, as members”. Labour’s Ruth Smeeth tells of abuse from Labour supporters, one ending in “hashtag Corbyn”.

The fact of such antisemitic abuse tells us much of the virulence of today’s identity politics. But if we cannot see or define the enemy, I cannot see how we can judge the scale of the threat. We really don’t know if Labour is a victim of some devious twist in its own factionalism, or if the attacker is the Tories, the Russians, or a bunch of bigots. Labour is told to “get its house in order”, but not how to do so, apart from expelling the maverick Ken Livingstone.

Anyone who enters the public domain, even by writing an article, knows that this plague is becoming, in the words of Labour’s Luciana Berger, “more commonplace, more conspicuous and more corrosive”. Those who follow “threads” at the ends of online articles, even when censored, are surprised at the licence granted by anonymity. The remarks routinely directed at female and ethnic minority colleagues can be shocking.

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Labour MP applauded in Commons for antisemitism speech – video

We have been hearing much about the sale of personal data by Facebook and the accompanying intrusion into privacy. Psychologists worry at the impact the platforms have on vulnerable and impressionable people. Not a day passes without news of cyberbulling or cyber-attacks. We seem impotent in the face of what is increasingly accepted as a public menace lurking behind a private good.

The distinction between democracy and mob rule is as old as Aristotle’s Athens. It lay in the evolution of mediating institutions. The sales pitch of the early internet was its creation of a “global village” under the “democracy of the worldwide web”. A benign blanket of connectedness and concord would descend on the world, and peace would be assured. I cannot recall anyone predicting an unrestricted torrent of malice and hatred, the politics of mob rule, the stocks and public lynchings.

Historians of the French revolution struggle to identify the sans-culottes who briefly ruled the streets of Paris in 1794, with their dreaded portable guillotines. Simon Schama records them as mostly gangs just a few dozen strong, able to summon up a few more idle dissidents to break up a meeting or butcher a committee. Operating outside the control of any authority they tore asunder a regime with, says Schama, “no more than two or three thousand committed revolutionary zealots”. The sans-culottes were not a democracy of the street, but pure anarchy.

If I go into a pub and am greeted by a wall of abuse, I can leave the pub. Likewise, I can steer clear of Facebook and Twitter. If I wish to write an unpopular article, I can take comfort that Britain does not allow sticks and stones to hurt me. But social media platforms have become public forums where politicians feel they must put in an appearance. In my view, as with any public forum, these platforms must have rules, including some identification of participants – or things will just get worse.

Governments have found ways to regulate international copyright, intellectual property and personal privacy. They have curbed hate speech. In The Net Delusion, Evgeny Morozov charted the danger to democracy in “a free-for-all anonymous internet culture”. The internet is indeed revolutionary, but if history teaches anything, it is that even revolutions must invent rules and courtesies. Donald Trump should be warning enough that we need to restore order and dignity to political discourse or it will simply degenerate into mouths screaming.

Jamie Bartlett, author of the forthcoming The People Vs Tech, ponders whether social media might go the whole hog and force contributors to give a unique identifier. He is reluctant as he feels these companies know enough about us as it is. He is more in favour of Germany’s savage fines for platforms that do not remove racist material in an instant. But he accepts that doing nothing is no longer enough.

I would go further and remove anything from social media that is posted by a source that the reader, or at least some moderator, cannot identify. Politics is precious. If you want to participate in the house of democracy, you must register at the door. There will still be abuse, but at least we can unmask the abusers.

Simon Jenkins is a Guardian columnist