Deindividuation is what happens when we get behind the wheel of a car and feel moved to scream abuse at the woman in front who is slow in turning right. It is what motivates a responsible father in a football crowd to yell crude sexual hatred at the opposition or the referee. And it's why under the cover of an alias or an avatar on a website or a blog – surrounded by virtual strangers – conventionally restrained individuals might be moved to suggest a comedian should suffer all manner of violent torture because they don't like his jokes, or his face. Digital media allow almost unlimited opportunity for wilful deindividuation. They almost require it.