There are hopeful signs that Facebook is starting to understand its power

Editorial: Unfashionable as it may be to point out, trying to restrain anyone’s postings on social media, let alone Donald Trump’s, is a near-impossible task

Mark Zuckerberg’s company says it is trying to combat political disinformation (AFP/Getty)

It’s a start. Sir Nick Clegg’s admission, on behalf of his current employers, Facebook, that it failed to prevent Russian interference in western elections, is a significant one. Even more welcome is the pledge from this giant among tech giants that it will try to block such state-sponsored foreign propaganda in future. The platform will also attempt to moderate the material generated by Donald Trump’s election campaign (and others), though not, seemingly, that which emanates from the president himself, who just happens to be a candidate.

Sir Nick regards the Trumpian messages about looting and shooting or setting vicious dogs on demonstrators as “abhorrent”, but defends the president’s right to say such things because they represent government policy, which is stretching a point. It is not an entirely satisfactory, nor consistent stance. It seems an untidy compromise – but Sir Nick is well used to those.

Unfashionable as it may be to point out, trying to restrain anyone’s postings on social media, let alone Mr Trump’s, is a near-impossible task. Despite all manner of filtering and reporting mechanisms, and the “pile-on” style of self-regulation by users, the sheer volume of material on social media, some produced by armies of bots, is impossible to police. Hence Facebook’s move to allow users to block political advertising, tricky though that may prove in practice.