Facebook provides a fun, free and remarkably popular service to 2.2bn users around the world. But the downside, and it is a very big one, is that the social network has opened the door for extremists, propagandists and spies to hack democracy.

One of the most damning charge sheets against Facebook — and other social media companies — was laid out recently in a British parliamentary report on disinformation and “fake news”. “Our democracy is at risk, and now is the time to act, to protect our shared values and the integrity of our democratic institutions,” it concluded.

Social networks that were designed to build communities have all too often been used to split societies. A report this year from the Oxford Internet Institute found evidence of organised social media manipulation campaigns in 48 countries, compared with 28 last year. These campaigns are also spreading to other platforms: in the developing world many of them run on chat apps, such as WhatsApp, Telegram and WeChat.