There is a chapter in my book which I called "We all have a volume control on mob rule". We all have a choice online as to whether fan flames, douse them, or stand by and watch a blaze.
It just occurred to me that every troll who indulged in the appalling bullying of Caroline Criado-Perez on Twitter recently must have people following them who found their behaviour unacceptable. They can't all have set up false, anonymous accounts because to do so would be like shouting in the dark ,and sort of defeat the point, as even bad behaviour needs an audience of more than one to be worth it. Bullies gain strength from that audience. The audience is to blame for not saying anything. Sure their hardcore mates would have egged them on but there must have been some at the periphery who felt uncomfortable and should have spoken up.
Yes I think Twitter should take some responsibility for what happens on their platform, and yes I think the police should get involved if criminal acts have been committed. But I also believe that more of us should take the often tough decision to stand up and say something when we see others in our circles indulging in unacceptable behaviour.