Five years ago a young woman broke up with her boyfriend, who was so offended by this that he posted nearly 10,000 words of misery and self-justification to the internet – and set in motion a movement which became known as “Gamergate”. Not only the woman but others who came to her defence were threatened with rape and murder by strangers. Companies who advertised on sites which took her side were pressured to withdraw their advertisements, and some, such as Intel, did so.

The reasons offered for this vileness were multifarious and incoherent, but included the false claim that Zoë Quinn, the original target, had slept with a journalist to ensure a favourable review of a computer game she had written. But the emotions behind it formed a coherent bundle. This was the contagious rage of men who felt themselves despised and dispossessed except when they sat at a keyboard.

Elements of this toxic brew had been around since the dawn of mass communication. The use of private and personal details to flay someone in public for the pleasure of strangers was pioneered by the tabloid press. But Gamergate revealed that the power of bullying has been redistributed online, so that the harassment once generally reserved for victims who might be described as famous could now be turned on anyone at all. The new movement was leaderless and self-organising, like a mob. No one could call off the furies it unleashed while the animating spirits could shelter behind the pseudonymity offered by forums including 4chan and 8chan. This anger spread like fire: those wounded by it flared back.

The second horror to emerge was a particular style of entitled and embittered masculinity. Attacks on women were the start of the movement and remained its prime concern: “Feminists have ruined my life and I will have my revenge, for my sake and for the sake of all the others they have wronged,” wrote one young man, threatening a mass shooting at a university if a talk by a woman on Gamergate was not cancelled.

These poisons have now leached into the main body of politics. Misogyny is now as well established in the culture of the far right as it is among the jihadists they hate. So are fantasies of cleansing violence. The exploitation of Twitter and YouTube as the media of choice for propaganda can also now be taken for granted. Until and unless the advertising companies who own them take this style of threat to society seriously, significant change is unlikely.

The original fury of Gamergate was sparked by the emergence of games as a cultural form which could be used to convey much more than the simple pleasures of blasting imaginary enemies – and was beginning to attract newly diverse audiences. This process continues. No one subculture – not even teenage white boys – now owns games. This opening up was, and remains, a source of fury. But perhaps, five years on, it should also be viewed as a reason to hope.