A few days back a vicious knife attack happened on  a london suburban train later that same day two people were knifed at kennington tube station south london.One person was a bystander who tried to intervene.  The train suburban carriage was not full ,passengers those their filmed the attack , called the police and some we’re shouting stop etc. the train stabbing attack film has been widely circulated on the news etc. I would be very interested in peoples views if they were in the carriage would they do different to what the other passengers did would they consider physical intervene? What other options if any.