Marjorie Taylor Greene is nuttier than M&M World. Not your garden-variety conservative, or even a conservative at all, but a conspiracy theorist who rode these febrile times into a seat in Congress.

She describes American Airlines Flight 77 as ‘the so-called plane that crashed into the Pentagon’ on 9/11, remarking that ‘it’s odd there’s never any evidence shown for a plane in the Pentagon’. She suspects the 2018 California wildfires were started by a Rothschild-funded ‘laser beam or light beam coming down to Earth’ in order to help Democrats build a high-speed rail project. Her Facebook account has liked a post proposing ‘a bullet to the head’ for Nancy Pelosi. All things considered, she’s lucky to have escaped with just a Twitter ban.

The congresswoman’s personal Twitter account has been permanently suspended ‘for repeated violations of (Twitter’s) Covid-19 misinformation policy’. She had been temporarily booted in the past for spreading what Twitter considers misinformation, but reportedly the final straw was a tweet alleging ‘extremely high amounts of Covid vaccine deaths’. While she has responded to her ban by accusing Twitter of being ‘an enemy to America’ and of pursuing ‘a communist revolution’, it’s hardly unreasonable for Twitter to rid itself of a high-profile user promoting vaccine misinformation during a pandemic.

This is not a question of free speech. Twitter is not the state and is under no obligation to provide anyone with a platform. It could adopt a ‘No Marjorie Taylor Greenes’ policy if it so wished. Their house, their rules.

Where things begin to get complicated is the fact that she is the Congresswoman for the Georgia 14th, where 75 per cent of voters cast a ballot for her in 2020. This in itself does not confer any special entitlement to a Twitter account, but it adds an extra dimension to the decision to suspend her. Although only her personal account has been deleted, Twitter has removed a channel of communication between an elected representative and the people she represents. Representative democracy will sometimes involve a lawmaker issuing stupid or false statements — indeed, this may be what appeals to their constituents — or making claims at odds with government or corporate policies, scientific or medical consensus, or public opinion.

So how does Twitter judge what constitutes misinformation? Had it been around when the MMR jab was falsely linked to autism, politicians who asserted the link may have been booted. But might Twitter have booted people out when the early warnings about thalidomide came? Or mesh implants? Or trans fats? We even have a contemporary example with the lab leak theory for Covid’s origins, which was rated false by mainstream media fact-checkers before it had been given the breathing space of the public square.

Social media is the means citizens use to discuss ideas, so it’s important who sets the rules. While nuking MTG’s personal account might be reasonable given her constant espousal of conspiracy theories and extremist politics, it places an onus of consistency on Twitter that is difficult to meet. If asserting that the 2020 election was stolen by Joe Biden is misinformation, is the same true of claiming that the 2000 election was stolen by George W Bush? If pushing the QAnon conspiracy theory undermines ‘civic integrity’, does pushing the claims that Trump was a Russian asset or being blackmailed by the Kremlin over a sex tape do the same?

Misinformation is discussed most in an American context, but British politicians are also found guilty. Left-wing MPs routinely assert that Conservative governments are plotting to privatise and sell off the NHS. This is plainly a conspiracy theory. Is there a more obvious attack on ‘civic integrity’ than spreading the claim that the government is conspiring to undermine its citizens’ healthcare for profit? Yet imagine what would happen if a Labour MP had their Twitter account suspended for spreading it.

If there is a defence for Twitter, it is surely harm reduction. MTG’s statements could encourage vaccine refusal or prompt January 6-style disorder. But outside the US, the stakes can be higher. In May 2021, Israeli police were dispatched to Jerusalem’s Temple Mount to bring a Palestinian riot at the sacred site under control. Numerous western politicians, presumably relying on propagandistic accounts of events, used Twitter to accuse Israel of an aggressive act, with this tweet from Nicola Sturgeon being typical:

Attacking a place of worship at any time is reprehensible, but attacking a mosque during Ramadan is utterly indefensible. It is also a violation of international law. Israel should heed calls to halt the violence immediately. #SheikhJarrah https://t.co/4H4Bu8MCwh

— Nicola Sturgeon (@NicolaSturgeon) May 8, 2021

The potential for such incendiary misinformation to contribute to ongoing violence is surely as obvious as false claims of electoral fraud were on January 6. These questions are raised not as whataboutery, but ‘whatstandardry’: what standard is being applied in making these decisions? The old public square was governed by laws, rules and customs, which were generally known. The new public square, as a creature of Silicon Valley developers, is markedly less transparent and democratic.

The tension between Big Tech and democracy should make us more uncomfortable about the MTG ban than we might want to be. Yes, she’s a loon, but is she more of a loon — or a more dangerous loon — than Ayatollah Khamenei? He is allowed to tweet that ‘the only remedy until the removal of the Zionist regime is firm, armed resistance’; that Jared Kushner is ‘the Jewish member of Trump’s family’, and that the US acts with ‘filthy Zionist agents’; and ask ‘why is it a crime to raise doubts about the Holocaust?’ For that matter, a cursory glance at what regime figures in Beijing are permitted to tweet about the Hong Kong opposition would suggest a double standard between democracies and dictatorships. No wonder: the latter wouldn’t be quite so accommodating of Twitter’s ideological caprices.

It’s not only dictatorships that should fear the power of social media. Democracies should too. If we accept that social media is our public square, should private companies decide who can participate in it? Should there limits placed on these companies about suspending accounts? Or should the conversation be about competition and the dangers of concentrating too much power in corporate hands? Marjorie Taylor Greene is hardly democracy’s greatest ambassador, but the democratic ideal is not so finished that it should be replaced by the ethics of a smiley corporatocracy.