A ruling at the Appeal Court in London yesterday could set a dangerous precedent on one of the most important issues in online free speech. The ruling could mean that Internet Service Providers such as Google and Facebook become recognised as “publishers” of material, rather than “mere conduits” and thus legally responsible for material posted on their platforms.

The case, brought by aspiring Conservative politician Payam Tamiz against Google*, hinged on whether or not Google was responsible for comments posted on a blog hosted on its Blogger blogging platform. Tamiz claimed to have been libelled by the “London Muslim” blog, which was hosted on the platform. He had approached Google to ask the blogger to remove the defamatory comments. After five weeks, Google did approach the blogger, asking him to delete the alleged slurs, which he duly did. But Tamiz continued to pursue a case against Google.

Tamiz initially lost his case, and, it should be noted, he lost his appeal this week too.

But the ruling on the appeal raises some interesting questions, and could pave the way for future actions against Internet Service Providers.

The key question seems to be what is a respectable time between being told of alleged defamatory publications, and actually becoming responsible for them.

Referring to Byrne v Deane, a 1937 case involving a defamatory note posted on a golf club notice board, the Master of the Rolls, Lord Justice Richards, commented that “[…]it is in my view open to argument that the time taken was sufficiently long to leave room for an inference adverse to Google Inc on Byrne v Deane principles.

“The period during which Google Inc might fall to be treated on that basis as a publisher of the defamatory comments would be a very short one, but it means that the claim cannot in my view be dismissed on the ground that Google Inc was clearly not a publisher of the comments at all.”

The suggestion is that eventually, Google does become responsible for content.

This reads like a threat to the concept of “mere conduit”, the concept enshrined in the European Union e-Commerce Directive establishing that ISPs cannot be held responsible for content on third party blogs, Facebook updates, tweets etc.

That concept is increasingly coming under threat. Just recently, Belfast lawyer Paul Tweed suggested to the Guardian that companies such as Google, Facebook and Twitter could be subject to “EU defamation cases”, in the courts in Ireland, where all three companies have major European bases.

Such a move could seriously threaten the way the web works. We rely on private ISPs to host our various interactions. Making them legally responsible for everything we post could lead to a situation where they severely narrow their terms of service, and even attempt to engage in some kind of censorship in order to avoid litigation. This shift in responsibility is not what the ISPs want, and certainly not what web users need.

*Google is one of Index on Censorship’s funders. Index’s editorial positions are independent of all its funders