This week brought the surprising news that Ravelry, a social network for knitters and needlework enthusiasts, has banned posts in support of US President Donald Trump, equating them with “open white supremacy”.

While Ravelry’s censorship will seem heavy-handed to some, members of the Jewish community, exasperated by the rising tide of antisemitism on social media, may well hope Facebook and Twitter followed suit.

Depending on which side of the censorship debate you stand, blockchain will either represent an ideal solution or the greatest danger of all.

Blockchain, the record-keeping technology behind the Bitcoin cryptocurrency, differs from traditional, centralised databases in that information is publicly available to all along the chain.

Rather than relying on a centralised authority – such as a bank – security from fraud is ensured through the constant validation of transactions by each participant along the chain.

As entrepreneurs rush to use the technology to create social media platforms, concerns have been raised over the ability to censor extreme or offensive material – precisely because the data will be de-centralised.

Gal Hochberg, the co-founder and CEO of tech firm Clear, which builds blockchain-based trade networks, said that large-scale blockchain-based social networks will be viable in “two to three years”.

The primary stumbling blocks relate to “scalability”, since it requires all parties – or at least a number of trusted parties – to store all the data held by the social network.

Speaking at the UK Israel Business Innovate 2019 conference in central London, Mr Hochberg told the JC that blockchain represents a “risk” to combating hate speech, which will require increased vigilance.

Mr Hochberg, whose company is Singaporean but has operations in Israel, said: “I think that in the post-truth world, which is the one we’re sadly living in, we have to think about our media in a smarter way in general, and how we will be able to combat these things.

“It’s both the consumers’ responsibility to be more careful in what they consume, and it’s for people who build the networks to be more responsible in building the right tools in to do those things.”

Authorities will still be able to apply pressure to individuals and companies responsible for hosting antisemitic material, he said. Similarly, app stores will be able to unilaterally blacklist offending networks.

Encryption technology also means that, strictly speaking, the identity of the users or owners of such sites could remain anonymous.

Traditional tools used to cut off funding to sites – such as the closing of bank and PayPal accounts – will also be rendered useless if cryptocurrencies are instead used to fund operations and incentivise “validation” of data.

Mr Hochberg likened future blockchain-based social networks to newspapers, saying they will be harder to censor, and instead will be combated by moderate users “choosing not to read”.

The technology could prove a force for good, he added, saying it could help to “shift the dynamic” away from overzealous censorship.

He said: “There’s no way to prevent people from posting it. ‘Impossible’ is a word I use carefully, but it would be prohibitively difficult. You could stop engaging, but it still wouldn’t stop it from being posted.

“If people are using the social network, and it has content which has a problem with ‘fake news’ – there is not really a good solution.

“But some people may see it as the future. They might say that now they can talk about stuff they care about. There are opinions that are clearly controversial, and there are opinions that are clearly not. And then there are things that are on the border. Some people will like censors, and some people won’t.

“I think it’s important to get educated about what it means for there to be un-censorable social networks and understand where that’s powerful, and where that’s dangerous.”